Don’t count on dung Conservationists (自然保护主义者) may be miscalculating the numbers of the threatened animals such as elephants, say African and American researchers. The error occurs because of a flaw in the way they estimate animal numbers from the piles of dung (粪) the creatures leave behind. The mistake could lead researchers to think that there are twice as many elephants as there really are in some regions, according to Andrew Plumptre of the Wildlife Conservation Society (WCS) in New York. Biologist Katy Payne of Cornell University in Ithaca, New York, agrees. "We really need to know elephant numbers and the evidence that we have is quite indirect," says Payne, who electronically tracks elephants. Counting elephants from planes is impossible in the vast rainforests of Central Africa. So researchers often estimate elephant numbers by counting dung piles in a given area. They also need to know the rate at which dung decays: Because it's extremely difficult to determine these rates, however, researchers counting elephants in one region tend to rely on standard decay rates established elsewhere. But researchers at the WCS have found that this decay rate varies from region to region depending on the climate and environment. Using the wrong values can lead the census astray (离开正道), says Plumptre. He and his colleague Anthony Chifu Nchanji studied decaying elephant dung in the forests of Cameroon. They found that the dung decayed between 55 and 65 per cent more slowly than the dung in the rainforests of neighbouring Gabon. If researchers use decay rates from Gabon to count elephants in Cameroon, they would probably find more elephants than are actually around. This could mean estimates in Cameroon are at least twice as high as those derived from decay rates calculated locally, says Plumptre. "However accurate your dung density estimate might be, the decay rate can severely affect the result." Plumptre also says that the dung-pile census should be carried out over a region similar in size to an elephant's natural range. The usual technique of monitoring only small, protected areas distorts numbers because elephants move in and out of these regions, he says. "If the elephant population increases within the protected area, you can not determine whether it is a real increase or whether it is due to elephants moving in because they are being poached (入侵偷猎) outside." Plumptre says that similar problems may also affect other animal census studies that rely on indirect evidence such as nests, tracks or burrows (地洞).文章(31~35)The word "threatened" in the first sentence of the first paragraph could be best replaced byA "endangered".B "frightened".C "killed".D "angered".
Don’t count on dung
Conservationists (自然保护主义者) may be miscalculating the numbers of the threatened animals such as elephants, say African and American researchers. The error occurs because of a flaw in the way they estimate animal numbers from the piles of dung (粪) the creatures leave behind.
The mistake could lead researchers to think that there are twice as many elephants as there really are in some regions, according to Andrew Plumptre of the Wildlife Conservation Society (WCS) in New York.
Biologist Katy Payne of Cornell University in Ithaca, New York, agrees. "We really need to know elephant numbers and the evidence that we have is quite indirect," says Payne, who electronically tracks elephants.
Counting elephants from planes is impossible in the vast rainforests of Central Africa. So researchers often estimate elephant numbers by counting dung piles in a given area. They also need to know the rate at which dung decays: Because it's extremely difficult to determine these rates, however, researchers counting elephants in one region tend to rely on standard decay rates established elsewhere.
But researchers at the WCS have found that this decay rate varies from region to region depending on the climate and environment. Using the wrong values can lead the census astray (离开正道), says Plumptre.
He and his colleague Anthony Chifu Nchanji studied decaying elephant dung in the forests of Cameroon. They found that the dung decayed between 55 and 65 per cent
more slowly than the dung in the rainforests of neighbouring Gabon. If researchers use decay rates from Gabon to count elephants in Cameroon, they would probably find more elephants than are actually around.
This could mean estimates in Cameroon are at least twice as high as those derived from decay rates calculated locally, says Plumptre. "However accurate your dung density estimate might be, the decay rate can severely affect the result."
Plumptre also says that the dung-pile census should be carried out over a region similar in size to an elephant's natural range. The usual technique of monitoring only small, protected areas distorts numbers because elephants move in and out of these regions, he says. "If the elephant population increases within the protected area, you can not determine whether it is a real increase or whether it is due to elephants moving in because they are being poached (入侵偷猎) outside."
Plumptre says that similar problems may also affect other animal census studies that rely on indirect evidence such as nests, tracks or burrows (地洞).
文章(31~35)
The word "threatened" in the first sentence of the first paragraph could be best replaced by
Conservationists (自然保护主义者) may be miscalculating the numbers of the threatened animals such as elephants, say African and American researchers. The error occurs because of a flaw in the way they estimate animal numbers from the piles of dung (粪) the creatures leave behind.
The mistake could lead researchers to think that there are twice as many elephants as there really are in some regions, according to Andrew Plumptre of the Wildlife Conservation Society (WCS) in New York.
Biologist Katy Payne of Cornell University in Ithaca, New York, agrees. "We really need to know elephant numbers and the evidence that we have is quite indirect," says Payne, who electronically tracks elephants.
Counting elephants from planes is impossible in the vast rainforests of Central Africa. So researchers often estimate elephant numbers by counting dung piles in a given area. They also need to know the rate at which dung decays: Because it's extremely difficult to determine these rates, however, researchers counting elephants in one region tend to rely on standard decay rates established elsewhere.
But researchers at the WCS have found that this decay rate varies from region to region depending on the climate and environment. Using the wrong values can lead the census astray (离开正道), says Plumptre.
He and his colleague Anthony Chifu Nchanji studied decaying elephant dung in the forests of Cameroon. They found that the dung decayed between 55 and 65 per cent
more slowly than the dung in the rainforests of neighbouring Gabon. If researchers use decay rates from Gabon to count elephants in Cameroon, they would probably find more elephants than are actually around.
This could mean estimates in Cameroon are at least twice as high as those derived from decay rates calculated locally, says Plumptre. "However accurate your dung density estimate might be, the decay rate can severely affect the result."
Plumptre also says that the dung-pile census should be carried out over a region similar in size to an elephant's natural range. The usual technique of monitoring only small, protected areas distorts numbers because elephants move in and out of these regions, he says. "If the elephant population increases within the protected area, you can not determine whether it is a real increase or whether it is due to elephants moving in because they are being poached (入侵偷猎) outside."
Plumptre says that similar problems may also affect other animal census studies that rely on indirect evidence such as nests, tracks or burrows (地洞).
文章(31~35)
The word "threatened" in the first sentence of the first paragraph could be best replaced by
A "endangered".
B "frightened".
C "killed".
D "angered".
B "frightened".
C "killed".
D "angered".
参考解析
解析：
相关考题：
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If cloned animals could be used as organ donors, ().A、people don’t have to worry about cloning twins for transplantsB、raising animals such as pigs can help solve the problemC、the human body attacks and destroys tissue from other speciesD、it may be more efficient to produce such animals by cloning than by cur
共用题干第三篇Longer Lives for Wild ElephantsMost people think of zoos as safe places for animals,where struggles such as having difficulty finding food and avoiding predators（猛兽）don't exist. Without such problems,animals in zoos should live to a ripe （成熟的）old age.But that may not be true for the largest land animals on Earth.Scientists have known that elephants in zoos often suffer from poor health.Sometimes,they even become unable to have babies.To learn more about how captivity（圈养）affects elephants, a team of international scientists compared the life spans of female elephants born in zoos with female elephants living outdoors in their native lands. Zoos keep detailed records of all the animals in their care,documenting factors such as birth dates,illnes-ses,weight and death.These records made it possible for the researchers to analyze 40 years of data on 800 African and Asian elephants in zoos across Europe.The scientists compared the life spans of the zoo-born fe-male elephants with the life spans of thousands of wild female elephants in Africa and Asian elephants that work in logging camps（伐木场）, over approximately the same time period.The team found that female African elephants born in zoos lived an average of 16.9 years. Their wild counterparts who died of natural causes lived an average of 56 years一more than three times as long. Female Asian elephants followed a similar pattern. In zoos,they lived 18.9 years,while those in the logging camps lived 41.7 years.Scientists don't know yet why wild elephants seem to get on so much better than their zoo-raised coun-terparts.Georgia Mason,a biologist at the University of Guelph in Canada who led the study,thinks stress and obesity（肥胖症）may be to blame. Zoo elephants don't get the same kind of exercise they would in the wild,and most are very fat. Social lives of elephants are also much different in zoos than in the wild,where they live in large herds and family groups.The study raises some questions about acquiring more elephants to keep in zoos.While some threatened and endangered species living in zoos reproduce（生殖）successfully and maintain healthy populations,that doesn't appear to be the case with elephants.Unlike other animals in zoos,zoo-raised elephantsA:live a long lifeB:give birth to many babiesC:develop poor healthD:have difficulty getting food
共用题干第三篇Longer Lives for Wild ElephantsMost people think of zoos as safe places for animals,where struggles such as having difficulty finding food and avoiding predators（猛兽）don't exist. Without such problems,animals in zoos should live to a ripe （成熟的）old age.But that may not be true for the largest land animals on Earth.Scientists have known that elephants in zoos often suffer from poor health.Sometimes,they even become unable to have babies.To learn more about how captivity（圈养）affects elephants, a team of international scientists compared the life spans of female elephants born in zoos with female elephants living outdoors in their native lands. Zoos keep detailed records of all the animals in their care,documenting factors such as birth dates,illnes-ses,weight and death.These records made it possible for the researchers to analyze 40 years of data on 800 African and Asian elephants in zoos across Europe.The scientists compared the life spans of the zoo-born fe-male elephants with the life spans of thousands of wild female elephants in Africa and Asian elephants that work in logging camps（伐木场）, over approximately the same time period.The team found that female African elephants born in zoos lived an average of 16.9 years. Their wild counterparts who died of natural causes lived an average of 56 years一more than three times as long. Female Asian elephants followed a similar pattern. In zoos,they lived 18.9 years,while those in the logging camps lived 41.7 years.Scientists don't know yet why wild elephants seem to get on so much better than their zoo-raised coun-terparts.Georgia Mason,a biologist at the University of Guelph in Canada who led the study,thinks stress and obesity（肥胖症）may be to blame. Zoo elephants don't get the same kind of exercise they would in the wild,and most are very fat. Social lives of elephants are also much different in zoos than in the wild,where they live in large herds and family groups.The study raises some questions about acquiring more elephants to keep in zoos.While some threatened and endangered species living in zoos reproduce（生殖）successfully and maintain healthy populations,that doesn't appear to be the case with elephants.Which of the following about the scientists'study is NOT true?A:They compared zoo-born elephants with wild elephants.B:They analyzed the records of 800 elephants kept in zoos.C:The zoo-born elephants they studied were kept in European zoos.D:They kept detailed records of all the elephants in their care.
共用题干第三篇Longer Lives for Wild ElephantsMost people think of zoos as safe places for animals,where struggles such as having difficulty finding food and avoiding predators（猛兽）don't exist. Without such problems,animals in zoos should live to a ripe （成熟的）old age.But that may not be true for the largest land animals on Earth.Scientists have known that elephants in zoos often suffer from poor health.Sometimes,they even become unable to have babies.To learn more about how captivity（圈养）affects elephants, a team of international scientists compared the life spans of female elephants born in zoos with female elephants living outdoors in their native lands. Zoos keep detailed records of all the animals in their care,documenting factors such as birth dates,illnes-ses,weight and death.These records made it possible for the researchers to analyze 40 years of data on 800 African and Asian elephants in zoos across Europe.The scientists compared the life spans of the zoo-born fe-male elephants with the life spans of thousands of wild female elephants in Africa and Asian elephants that work in logging camps（伐木场）, over approximately the same time period.The team found that female African elephants born in zoos lived an average of 16.9 years. Their wild counterparts who died of natural causes lived an average of 56 years一more than three times as long. Female Asian elephants followed a similar pattern. In zoos,they lived 18.9 years,while those in the logging camps lived 41.7 years.Scientists don't know yet why wild elephants seem to get on so much better than their zoo-raised coun-terparts.Georgia Mason,a biologist at the University of Guelph in Canada who led the study,thinks stress and obesity（肥胖症）may be to blame. Zoo elephants don't get the same kind of exercise they would in the wild,and most are very fat. Social lives of elephants are also much different in zoos than in the wild,where they live in large herds and family groups.The study raises some questions about acquiring more elephants to keep in zoos.While some threatened and endangered species living in zoos reproduce（生殖）successfully and maintain healthy populations,that doesn't appear to be the case with elephants.It was found that,compared with female wild elephants,female zoo-born elephants_______________.A:lived longerB:grew up fasterC:died much earlierD:enjoyed the same life spans
共用题干第三篇Longer Lives for Wild ElephantsMost people think of zoos as safe places for animals,where struggles such as having difficulty finding food and avoiding predators（猛兽）don't exist. Without such problems,animals in zoos should live to a ripe （成熟的）old age.But that may not be true for the largest land animals on Earth.Scientists have known that elephants in zoos often suffer from poor health.Sometimes,they even become unable to have babies.To learn more about how captivity（圈养）affects elephants, a team of international scientists compared the life spans of female elephants born in zoos with female elephants living outdoors in their native lands. Zoos keep detailed records of all the animals in their care,documenting factors such as birth dates,illnes-ses,weight and death.These records made it possible for the researchers to analyze 40 years of data on 800 African and Asian elephants in zoos across Europe.The scientists compared the life spans of the zoo-born fe-male elephants with the life spans of thousands of wild female elephants in Africa and Asian elephants that work in logging camps（伐木场）, over approximately the same time period.The team found that female African elephants born in zoos lived an average of 16.9 years. Their wild counterparts who died of natural causes lived an average of 56 years一more than three times as long. Female Asian elephants followed a similar pattern. In zoos,they lived 18.9 years,while those in the logging camps lived 41.7 years.Scientists don't know yet why wild elephants seem to get on so much better than their zoo-raised coun-terparts.Georgia Mason,a biologist at the University of Guelph in Canada who led the study,thinks stress and obesity（肥胖症）may be to blame. Zoo elephants don't get the same kind of exercise they would in the wild,and most are very fat. Social lives of elephants are also much different in zoos than in the wild,where they live in large herds and family groups.The study raises some questions about acquiring more elephants to keep in zoos.While some threatened and endangered species living in zoos reproduce（生殖）successfully and maintain healthy populations,that doesn't appear to be the case with elephants.It can be inferred from the last paragraph that______________.A:zoo-born elephants should be looked after more carefullyB:zoos should keep more animals except elephantsC:it may not be wise to keep elephants in zoosD:elephants are no longer an endangered species
共用题干第三篇Longer Lives for Wild ElephantsMost people think of zoos as safe places for animals,where struggles such as having difficulty finding food and avoiding predators（猛兽）don't exist. Without such problems,animals in zoos should live to a ripe （成熟的）old age.But that may not be true for the largest land animals on Earth.Scientists have known that elephants in zoos often suffer from poor health.Sometimes,they even become unable to have babies.To learn more about how captivity（圈养）affects elephants, a team of international scientists compared the life spans of female elephants born in zoos with female elephants living outdoors in their native lands. Zoos keep detailed records of all the animals in their care,documenting factors such as birth dates,illnes-ses,weight and death.These records made it possible for the researchers to analyze 40 years of data on 800 African and Asian elephants in zoos across Europe.The scientists compared the life spans of the zoo-born fe-male elephants with the life spans of thousands of wild female elephants in Africa and Asian elephants that work in logging camps（伐木场）, over approximately the same time period.The team found that female African elephants born in zoos lived an average of 16.9 years. Their wild counterparts who died of natural causes lived an average of 56 years一more than three times as long. Female Asian elephants followed a similar pattern. In zoos,they lived 18.9 years,while those in the logging camps lived 41.7 years.Scientists don't know yet why wild elephants seem to get on so much better than their zoo-raised coun-terparts.Georgia Mason,a biologist at the University of Guelph in Canada who led the study,thinks stress and obesity（肥胖症）may be to blame. Zoo elephants don't get the same kind of exercise they would in the wild,and most are very fat. Social lives of elephants are also much different in zoos than in the wild,where they live in large herds and family groups.The study raises some questions about acquiring more elephants to keep in zoos.While some threatened and endangered species living in zoos reproduce（生殖）successfully and maintain healthy populations,that doesn't appear to be the case with elephants.One of the possible reasons for the zoo-raised elephants'problems is that______________.A:they do not get proper food B:they do too much exerciseC:they live in large herdsD:they do not live in family groups
共用题干第二篇Don ' t Count on Dung" Conservationists（自然保护主义者）may be miscalculating the numbers of the threatened animals such as elephants."say African and American researchers.The error occurs because of a flaw in the way that they estimate animal numbers from the piles of dung（粪）the creatures leave behind.The mistake could lead researchers to think that there are twice as many elephants as there really are in some regions,according to Andrew Plumptre of the Wildlife Conservation Society(WCS)in New York.Biologist Katy Payne of Cornell University in Ithaca,New York,agrees."We really need to know ele- phant numbers and the evidence that we have is quite indirect,"says Payne,who electronically tracks elephants.Counting elephants from planes is impossible in the vast rainforests of Central Africa. So researchers of- ten estimate elephant numbers by counting dung piles in a given area.They also need to know the rate at which dung decays.Because it's extremely difficult to determine these rates,researchers counting elephants in one region tend to rely on standard decay rates established elsewhere.But researchers at the WCS have found that this decay rate varies from region to region depending on the climate and environment. " Using the wrong values can lead the census astray（离开正道）,"says Plumptre.He and his colleague Anthony Chifu Nchanji studied decaying elephant dung in the forests of Came- roon.They found that the dung decayed between 55 and 65 per cent more slowly than the dung in therainforests of neighbouring Gabon.If researchers use decay rates from Gabon to count elephants in Cameroon, they would probably find more elephants than are actually around."This could mean estimates in Cameroon are at least twice as high as those derived from decay rates calculated locally,"says Plumptre."However accurate your dung density estimate might be,the decay rate can severely affect the result."Plumptre also says that the dung-pile census should be carried out over a region similar in size to an ele- phant's natural range."The usual technique of monitoring only small,protected areas distorts numbers be-cause elephants move in and out of these regions,"he says."If the elephant population increases within the protected area,you cannot determine whether it is a real increase or whether it is due to elephants moving in because they are being poached（入侵偷猎）outside."Plumptre says that similar problems may also affect other animal census studies that rely on indirect evi-- dence such as nests,tracks or burrows（地洞）.Piles of dung can't be relied upon when it comes to estimating elephant numbers because_______.A:they are different in sizeB:they scatter all over the regionC:they are different in decay rateD:they are different in quality
共用题干第二篇Don ' t Count on Dung" Conservationists（自然保护主义者）may be miscalculating the numbers of the threatened animals such as elephants."say African and American researchers.The error occurs because of a flaw in the way that they estimate animal numbers from the piles of dung（粪）the creatures leave behind.The mistake could lead researchers to think that there are twice as many elephants as there really are in some regions,according to Andrew Plumptre of the Wildlife Conservation Society(WCS)in New York.Biologist Katy Payne of Cornell University in Ithaca,New York,agrees."We really need to know ele- phant numbers and the evidence that we have is quite indirect,"says Payne,who electronically tracks elephants.Counting elephants from planes is impossible in the vast rainforests of Central Africa. So researchers of- ten estimate elephant numbers by counting dung piles in a given area.They also need to know the rate at which dung decays.Because it's extremely difficult to determine these rates,researchers counting elephants in one region tend to rely on standard decay rates established elsewhere.But researchers at the WCS have found that this decay rate varies from region to region depending on the climate and environment. " Using the wrong values can lead the census astray（离开正道）,"says Plumptre.He and his colleague Anthony Chifu Nchanji studied decaying elephant dung in the forests of Came- roon.They found that the dung decayed between 55 and 65 per cent more slowly than the dung in therainforests of neighbouring Gabon.If researchers use decay rates from Gabon to count elephants in Cameroon, they would probably find more elephants than are actually around."This could mean estimates in Cameroon are at least twice as high as those derived from decay rates calculated locally,"says Plumptre."However accurate your dung density estimate might be,the decay rate can severely affect the result."Plumptre also says that the dung-pile census should be carried out over a region similar in size to an ele- phant's natural range."The usual technique of monitoring only small,protected areas distorts numbers be-cause elephants move in and out of these regions,"he says."If the elephant population increases within the protected area,you cannot determine whether it is a real increase or whether it is due to elephants moving in because they are being poached（入侵偷猎）outside."Plumptre says that similar problems may also affect other animal census studies that rely on indirect evi-- dence such as nests,tracks or burrows（地洞）.According to Plumptre,the region over which a dung-pile census is carried out should be_________.A:small enoughB:well protectedC:carefully monitoredD:large enough
共用题干第二篇Don ' t Count on Dung" Conservationists（自然保护主义者）may be miscalculating the numbers of the threatened animals such as elephants."say African and American researchers.The error occurs because of a flaw in the way that they estimate animal numbers from the piles of dung（粪）the creatures leave behind.The mistake could lead researchers to think that there are twice as many elephants as there really are in some regions,according to Andrew Plumptre of the Wildlife Conservation Society(WCS)in New York.Biologist Katy Payne of Cornell University in Ithaca,New York,agrees."We really need to know ele- phant numbers and the evidence that we have is quite indirect,"says Payne,who electronically tracks elephants.Counting elephants from planes is impossible in the vast rainforests of Central Africa. So researchers of- ten estimate elephant numbers by counting dung piles in a given area.They also need to know the rate at which dung decays.Because it's extremely difficult to determine these rates,researchers counting elephants in one region tend to rely on standard decay rates established elsewhere.But researchers at the WCS have found that this decay rate varies from region to region depending on the climate and environment. " Using the wrong values can lead the census astray（离开正道）,"says Plumptre.He and his colleague Anthony Chifu Nchanji studied decaying elephant dung in the forests of Came- roon.They found that the dung decayed between 55 and 65 per cent more slowly than the dung in therainforests of neighbouring Gabon.If researchers use decay rates from Gabon to count elephants in Cameroon, they would probably find more elephants than are actually around."This could mean estimates in Cameroon are at least twice as high as those derived from decay rates calculated locally,"says Plumptre."However accurate your dung density estimate might be,the decay rate can severely affect the result."Plumptre also says that the dung-pile census should be carried out over a region similar in size to an ele- phant's natural range."The usual technique of monitoring only small,protected areas distorts numbers be-cause elephants move in and out of these regions,"he says."If the elephant population increases within the protected area,you cannot determine whether it is a real increase or whether it is due to elephants moving in because they are being poached（入侵偷猎）outside."Plumptre says that similar problems may also affect other animal census studies that rely on indirect evi-- dence such as nests,tracks or burrows（地洞）.The first word"He"in Paragraph 6 refers to________.A:Andrew PlumptreB:Katy PayneC:Anthony Chifu NchanjiD:the writer of the article
共用题干第二篇Don ' t Count on Dung" Conservationists（自然保护主义者）may be miscalculating the numbers of the threatened animals such as elephants."say African and American researchers.The error occurs because of a flaw in the way that they estimate animal numbers from the piles of dung（粪）the creatures leave behind.The mistake could lead researchers to think that there are twice as many elephants as there really are in some regions,according to Andrew Plumptre of the Wildlife Conservation Society(WCS)in New York.Biologist Katy Payne of Cornell University in Ithaca,New York,agrees."We really need to know ele- phant numbers and the evidence that we have is quite indirect,"says Payne,who electronically tracks elephants.Counting elephants from planes is impossible in the vast rainforests of Central Africa. So researchers of- ten estimate elephant numbers by counting dung piles in a given area.They also need to know the rate at which dung decays.Because it's extremely difficult to determine these rates,researchers counting elephants in one region tend to rely on standard decay rates established elsewhere.But researchers at the WCS have found that this decay rate varies from region to region depending on the climate and environment. " Using the wrong values can lead the census astray（离开正道）,"says Plumptre.He and his colleague Anthony Chifu Nchanji studied decaying elephant dung in the forests of Came- roon.They found that the dung decayed between 55 and 65 per cent more slowly than the dung in therainforests of neighbouring Gabon.If researchers use decay rates from Gabon to count elephants in Cameroon, they would probably find more elephants than are actually around."This could mean estimates in Cameroon are at least twice as high as those derived from decay rates calculated locally,"says Plumptre."However accurate your dung density estimate might be,the decay rate can severely affect the result."Plumptre also says that the dung-pile census should be carried out over a region similar in size to an ele- phant's natural range."The usual technique of monitoring only small,protected areas distorts numbers be-cause elephants move in and out of these regions,"he says."If the elephant population increases within the protected area,you cannot determine whether it is a real increase or whether it is due to elephants moving in because they are being poached（入侵偷猎）outside."Plumptre says that similar problems may also affect other animal census studies that rely on indirect evi-- dence such as nests,tracks or burrows（地洞）.Why do researchers estimate elephant numbers in an area by counting dung piles?A:Because elephants are difficult to catch.B:Because it is not possible to count elephants from a plane.C:Because it is not possible to keep track of elephants.D:Because elephants are shy animals.
共用题干第二篇Don ' t Count on Dung" Conservationists（自然保护主义者）may be miscalculating the numbers of the threatened animals such as elephants."say African and American researchers.The error occurs because of a flaw in the way that they estimate animal numbers from the piles of dung（粪）the creatures leave behind.The mistake could lead researchers to think that there are twice as many elephants as there really are in some regions,according to Andrew Plumptre of the Wildlife Conservation Society(WCS)in New York.Biologist Katy Payne of Cornell University in Ithaca,New York,agrees."We really need to know ele- phant numbers and the evidence that we have is quite indirect,"says Payne,who electronically tracks elephants.Counting elephants from planes is impossible in the vast rainforests of Central Africa. So researchers of- ten estimate elephant numbers by counting dung piles in a given area.They also need to know the rate at which dung decays.Because it's extremely difficult to determine these rates,researchers counting elephants in one region tend to rely on standard decay rates established elsewhere.But researchers at the WCS have found that this decay rate varies from region to region depending on the climate and environment. " Using the wrong values can lead the census astray（离开正道）,"says Plumptre.He and his colleague Anthony Chifu Nchanji studied decaying elephant dung in the forests of Came- roon.They found that the dung decayed between 55 and 65 per cent more slowly than the dung in therainforests of neighbouring Gabon.If researchers use decay rates from Gabon to count elephants in Cameroon, they would probably find more elephants than are actually around."This could mean estimates in Cameroon are at least twice as high as those derived from decay rates calculated locally,"says Plumptre."However accurate your dung density estimate might be,the decay rate can severely affect the result."Plumptre also says that the dung-pile census should be carried out over a region similar in size to an ele- phant's natural range."The usual technique of monitoring only small,protected areas distorts numbers be-cause elephants move in and out of these regions,"he says."If the elephant population increases within the protected area,you cannot determine whether it is a real increase or whether it is due to elephants moving in because they are being poached（入侵偷猎）outside."Plumptre says that similar problems may also affect other animal census studies that rely on indirect evi-- dence such as nests,tracks or burrows（地洞）.The word"threatened"in the first sentence of the first paragraph could be best replaced by_________.A:"endangered"B:"frightened"C:"killed"D:"angered"
共用题干第二篇Don't Count on DungConservationists（自然保护主义者）may be miscalculating the numbers of the threatened animals such as elephants,say African and American researchers.The error occurs because of a flaw in the way they estimate animal numbers from the piles of dung （粪）the creatures leave behind.The mistake could lead researchers to think that there are twice as many elephants as there really are in some regions,according to Andrew Plumptre of the Wildlife Conservation Society(WCS)in New York.Biologist Katy Payne of Cornell University in Ithaca,New York,agrees.“We really need to know elephant numbers and the evidence that we have is quite indirect,"says Payne,who electronically tracks elephants.Counting elephants from planes is impossible in the vast rainforests of Central Africa.So researchers often estimate elephant numbers by counting dung piles in a given area.They also need to know the rate at which dung decays.Because it's extremely difficult to determine these rates,however,researchers counting elephants in one region tend to rely on standard decay rates established elsewhere.But researchers at the WCS have found that this decay rate varies from region to region depending on the climate and environment.Using the wrong values can lead the censusastray（离开正道）,says Plumptre.He and his colleague Anthony Chifu Nchanji studied decaying elephant dung in the forests of Cameroon.They found that the dung decayed between 55 and 65 per cent more slowly than the dung in the rainforests of neighbouring Gabon.If researchers use decay rates from Gabon to count elephants in Cameroon,they would probably find more elephants than are actually around.This could mean estimates in Cameroon are at least twice as high as those derived from decay rates calculated locally,says Plumptre."However accurate your dung densityestimate might be,the decay rate can severely affect the result.''Plumptre also says that the dung-pile census should be carried out over a region similar in size to an elephant's natural range.The usual technique of monitoring only small, protected areas distorts numbers because elephants move in and out of these regions,he says."If the elephant population increases within the protected area,you can not determine whether it is a real increase or whether it is due to elephants moving in because they are being poached（入侵偷猎）outside."Plumptre says that similar problems may also affect other animal census studies that rely on indirect evidence such as nests,tracks or burrows（地洞）.Why do researchers estimate elephant numbers in an area by counting dung piles?A:Because elephants are difficult to catch.B:Because it is not possible to count elephants from a plane.C:Because it is not possible to keep track of elephants.D:Because elephants are shy animals.
共用题干第三篇Animal Testing ControversyTo paraphrase 18th-century statesman Edmund Burke,"All that is needed for the triumph of a misguided cause is that good people do nothing." One such cause now seeks to end biomedical research because of the theory that animals have rights ruling out their use in research.Scientists need to respond forcefully to animal rights advocates,whose arguments are confusing the public and thereby threatening advances in health knowledge and care.Leaders of the animal rights movement target biomedical research because it depends on public funding,and few people understand the process of health care research.Hearing allegations of cruelty to animals in research settings,many are perplexed that anyone would deliberately harm an animal.For example,a grandmotherly woman staffing an animal rights booth at a recent street fair was distributing a brochure that encouraged readers not to use anything that comes from or is animals一no meat,no fur,no medicines.Asked if she opposed immunizations,she wanted to know if vaccines come from animal research.When assured that they do,she replied,"Then I would have to say yes."Asked what will happen when epidemics return,she said,"Don't worry,scientists will find some way of using computers."Such well-meaning people just don't understand.Scientists must communicate their message to the public in a compassionate,understandable way一in human terms,not in the language of molecular biology.We need to make clear the connection between animal research and a grandmother's hip replacement,a father's bypass operation,a baby's vaccinations,and even a pet's shots.To those who are unaware that animal research was nee-- ded to produce these treatments,as well as new treatments and vaccines,animal research seems wasteful at best and cruel at worst.Much can be done.Scientists could"adopt"middle school classes and present their own re-search.They should be quick to respond to letters to the editor,lest animal rights misinformation go unchallenged and acquire a deceptive appearance of truth.Research institutions could be opened to tours,to show that laboratory animals receive humane care.Finally,because the ultimate stakeholders are patients,the health research community should actively recruit to its cause not only well-known personalities such as Stephen Cooper,who has made courageous statements about the value of animal research,but all who receive medical treatment.If good people do nothing there is a real possibility that an uninformed citizenry will extinguish the precious embers of medical progress.From the text we learn that Stephen Cooper is________.A:a well-known humanist B:a medical practitionerC:an enthusiast in animal rights D:a supporter of animal research
共用题干第二篇Don't Count on DungConservationists（自然保护主义者）may be miscalculating the numbers of the threatened animals such as elephants,say African and American researchers.The error occurs because of a flaw in the way they estimate animal numbers from the piles of dung （粪）the creatures leave behind.The mistake could lead researchers to think that there are twice as many elephants as there really are in some regions,according to Andrew Plumptre of the Wildlife Conservation Society(WCS)in New York.Biologist Katy Payne of Cornell University in Ithaca,New York,agrees.“We really need to know elephant numbers and the evidence that we have is quite indirect,"says Payne,who electronically tracks elephants.Counting elephants from planes is impossible in the vast rainforests of Central Africa.So researchers often estimate elephant numbers by counting dung piles in a given area.They also need to know the rate at which dung decays.Because it's extremely difficult to determine these rates,however,researchers counting elephants in one region tend to rely on standard decay rates established elsewhere.But researchers at the WCS have found that this decay rate varies from region to region depending on the climate and environment.Using the wrong values can lead the censusastray（离开正道）,says Plumptre.He and his colleague Anthony Chifu Nchanji studied decaying elephant dung in the forests of Cameroon.They found that the dung decayed between 55 and 65 per cent more slowly than the dung in the rainforests of neighbouring Gabon.If researchers use decay rates from Gabon to count elephants in Cameroon,they would probably find more elephants than are actually around.This could mean estimates in Cameroon are at least twice as high as those derived from decay rates calculated locally,says Plumptre."However accurate your dung densityestimate might be,the decay rate can severely affect the result.''Plumptre also says that the dung-pile census should be carried out over a region similar in size to an elephant's natural range.The usual technique of monitoring only small, protected areas distorts numbers because elephants move in and out of these regions,he says."If the elephant population increases within the protected area,you can not determine whether it is a real increase or whether it is due to elephants moving in because they are being poached（入侵偷猎）outside."Plumptre says that similar problems may also affect other animal census studies that rely on indirect evidence such as nests,tracks or burrows（地洞）.According to Plumptre,the region over which a dung-pile census is carried out should beA:small enough.B:well protected.C:carefully monitored.D:large enough.
共用题干第二篇Don't Count on DungConservationists（自然保护主义者）may be miscalculating the numbers of the threatened animals such as elephants,say African and American researchers.The error occurs because of a flaw in the way they estimate animal numbers from the piles of dung （粪）the creatures leave behind.The mistake could lead researchers to think that there are twice as many elephants as there really are in some regions,according to Andrew Plumptre of the Wildlife Conservation Society(WCS)in New York.Biologist Katy Payne of Cornell University in Ithaca,New York,agrees.“We really need to know elephant numbers and the evidence that we have is quite indirect,"says Payne,who electronically tracks elephants.Counting elephants from planes is impossible in the vast rainforests of Central Africa.So researchers often estimate elephant numbers by counting dung piles in a given area.They also need to know the rate at which dung decays.Because it's extremely difficult to determine these rates,however,researchers counting elephants in one region tend to rely on standard decay rates established elsewhere.But researchers at the WCS have found that this decay rate varies from region to region depending on the climate and environment.Using the wrong values can lead the censusastray（离开正道）,says Plumptre.He and his colleague Anthony Chifu Nchanji studied decaying elephant dung in the forests of Cameroon.They found that the dung decayed between 55 and 65 per cent more slowly than the dung in the rainforests of neighbouring Gabon.If researchers use decay rates from Gabon to count elephants in Cameroon,they would probably find more elephants than are actually around.This could mean estimates in Cameroon are at least twice as high as those derived from decay rates calculated locally,says Plumptre."However accurate your dung densityestimate might be,the decay rate can severely affect the result.''Plumptre also says that the dung-pile census should be carried out over a region similar in size to an elephant's natural range.The usual technique of monitoring only small, protected areas distorts numbers because elephants move in and out of these regions,he says."If the elephant population increases within the protected area,you can not determine whether it is a real increase or whether it is due to elephants moving in because they are being poached（入侵偷猎）outside."Plumptre says that similar problems may also affect other animal census studies that rely on indirect evidence such as nests,tracks or burrows（地洞）.The word "threatened" in the first sentence of the first paragraph could be best replaced byA:"endangered".B:"frightened".C:"killed".D:"angered".
共用题干第三篇Animal Testing ControversyTo paraphrase 18th-century statesman Edmund Burke,"All that is needed for the triumph of a misguided cause is that good people do nothing." One such cause now seeks to end biomedical research because of the theory that animals have rights ruling out their use in research.Scientists need to respond forcefully to animal rights advocates,whose arguments are confusing the public and thereby threatening advances in health knowledge and care.Leaders of the animal rights movement target biomedical research because it depends on public funding,and few people understand the process of health care research.Hearing allegations of cruelty to animals in research settings,many are perplexed that anyone would deliberately harm an animal.For example,a grandmotherly woman staffing an animal rights booth at a recent street fair was distributing a brochure that encouraged readers not to use anything that comes from or is animals一no meat,no fur,no medicines.Asked if she opposed immunizations,she wanted to know if vaccines come from animal research.When assured that they do,she replied,"Then I would have to say yes."Asked what will happen when epidemics return,she said,"Don't worry,scientists will find some way of using computers."Such well-meaning people just don't understand.Scientists must communicate their message to the public in a compassionate,understandable way一in human terms,not in the language of molecular biology.We need to make clear the connection between animal research and a grandmother's hip replacement,a father's bypass operation,a baby's vaccinations,and even a pet's shots.To those who are unaware that animal research was nee-- ded to produce these treatments,as well as new treatments and vaccines,animal research seems wasteful at best and cruel at worst.Much can be done.Scientists could"adopt"middle school classes and present their own re-search.They should be quick to respond to letters to the editor,lest animal rights misinformation go unchallenged and acquire a deceptive appearance of truth.Research institutions could be opened to tours,to show that laboratory animals receive humane care.Finally,because the ultimate stakeholders are patients,the health research community should actively recruit to its cause not only well-known personalities such as Stephen Cooper,who has made courageous statements about the value of animal research,but all who receive medical treatment.If good people do nothing there is a real possibility that an uninformed citizenry will extinguish the precious embers of medical progress.The author believes that,in face of the challenge from animal rights advocates,scientists should________.A:communicate more with the publicB:employ hi-tech means in researchC:feel no shame for their causeD:strive to develop new cures
共用题干第二篇Don't Count on DungConservationists（自然保护主义者）may be miscalculating the numbers of the threatened animals such as elephants,say African and American researchers.The error occurs because of a flaw in the way they estimate animal numbers from the piles of dung （粪）the creatures leave behind.The mistake could lead researchers to think that there are twice as many elephants as there really are in some regions,according to Andrew Plumptre of the Wildlife Conservation Society(WCS)in New York.Biologist Katy Payne of Cornell University in Ithaca,New York,agrees.“We really need to know elephant numbers and the evidence that we have is quite indirect,"says Payne,who electronically tracks elephants.Counting elephants from planes is impossible in the vast rainforests of Central Africa.So researchers often estimate elephant numbers by counting dung piles in a given area.They also need to know the rate at which dung decays.Because it's extremely difficult to determine these rates,however,researchers counting elephants in one region tend to rely on standard decay rates established elsewhere.But researchers at the WCS have found that this decay rate varies from region to region depending on the climate and environment.Using the wrong values can lead the censusastray（离开正道）,says Plumptre.He and his colleague Anthony Chifu Nchanji studied decaying elephant dung in the forests of Cameroon.They found that the dung decayed between 55 and 65 per cent more slowly than the dung in the rainforests of neighbouring Gabon.If researchers use decay rates from Gabon to count elephants in Cameroon,they would probably find more elephants than are actually around.This could mean estimates in Cameroon are at least twice as high as those derived from decay rates calculated locally,says Plumptre."However accurate your dung densityestimate might be,the decay rate can severely affect the result.''Plumptre also says that the dung-pile census should be carried out over a region similar in size to an elephant's natural range.The usual technique of monitoring only small, protected areas distorts numbers because elephants move in and out of these regions,he says."If the elephant population increases within the protected area,you can not determine whether it is a real increase or whether it is due to elephants moving in because they are being poached（入侵偷猎）outside."Plumptre says that similar problems may also affect other animal census studies that rely on indirect evidence such as nests,tracks or burrows（地洞）.The first word"He"in paragraph 6 refers toA:Andrew Plumptre.B:Katy Payne.C:Anthony Chifu Nchanji.D:the writer of the article.
Why do researchers estimate elephant numbers in an area by counting dung piles?A Because elephants are difficult to catch.B Because it is not possible to count elephants from a plane.C Because it is not possible to keep track of elephants.D Because elephants are shy animals.
共用题干第三篇Animal Testing ControversyTo paraphrase 18th-century statesman Edmund Burke,"All that is needed for the triumph of a misguided cause is that good people do nothing." One such cause now seeks to end biomedical research because of the theory that animals have rights ruling out their use in research.Scientists need to respond forcefully to animal rights advocates,whose arguments are confusing the public and thereby threatening advances in health knowledge and care.Leaders of the animal rights movement target biomedical research because it depends on public funding,and few people understand the process of health care research.Hearing allegations of cruelty to animals in research settings,many are perplexed that anyone would deliberately harm an animal.For example,a grandmotherly woman staffing an animal rights booth at a recent street fair was distributing a brochure that encouraged readers not to use anything that comes from or is animals一no meat,no fur,no medicines.Asked if she opposed immunizations,she wanted to know if vaccines come from animal research.When assured that they do,she replied,"Then I would have to say yes."Asked what will happen when epidemics return,she said,"Don't worry,scientists will find some way of using computers."Such well-meaning people just don't understand.Scientists must communicate their message to the public in a compassionate,understandable way一in human terms,not in the language of molecular biology.We need to make clear the connection between animal research and a grandmother's hip replacement,a father's bypass operation,a baby's vaccinations,and even a pet's shots.To those who are unaware that animal research was nee-- ded to produce these treatments,as well as new treatments and vaccines,animal research seems wasteful at best and cruel at worst.Much can be done.Scientists could"adopt"middle school classes and present their own re-search.They should be quick to respond to letters to the editor,lest animal rights misinformation go unchallenged and acquire a deceptive appearance of truth.Research institutions could be opened to tours,to show that laboratory animals receive humane care.Finally,because the ultimate stakeholders are patients,the health research community should actively recruit to its cause not only well-known personalities such as Stephen Cooper,who has made courageous statements about the value of animal research,but all who receive medical treatment.If good people do nothing there is a real possibility that an uninformed citizenry will extinguish the precious embers of medical progress.Misled people tend to think that using an animal in research is________.A:cruel but naturalB:inhuman and unacceptableC:inevitable but viciousD:pointless and wasteful
Piles of dung can't be relied upon when it comes to estimating elephant numbers becauseA they are different in size.B they scatter all over the region.C they are different in decay rate.D they are different in quality.
共用题干第二篇Don't Count on DungConservationists（自然保护主义者）may be miscalculating the numbers of the threatened animals such as elephants,say African and American researchers.The error occurs because of a flaw in the way they estimate animal numbers from the piles of dung （粪）the creatures leave behind.The mistake could lead researchers to think that there are twice as many elephants as there really are in some regions,according to Andrew Plumptre of the Wildlife Conservation Society(WCS)in New York.Biologist Katy Payne of Cornell University in Ithaca,New York,agrees.“We really need to know elephant numbers and the evidence that we have is quite indirect,"says Payne,who electronically tracks elephants.Counting elephants from planes is impossible in the vast rainforests of Central Africa.So researchers often estimate elephant numbers by counting dung piles in a given area.They also need to know the rate at which dung decays.Because it's extremely difficult to determine these rates,however,researchers counting elephants in one region tend to rely on standard decay rates established elsewhere.But researchers at the WCS have found that this decay rate varies from region to region depending on the climate and environment.Using the wrong values can lead the censusastray（离开正道）,says Plumptre.He and his colleague Anthony Chifu Nchanji studied decaying elephant dung in the forests of Cameroon.They found that the dung decayed between 55 and 65 per cent more slowly than the dung in the rainforests of neighbouring Gabon.If researchers use decay rates from Gabon to count elephants in Cameroon,they would probably find more elephants than are actually around.This could mean estimates in Cameroon are at least twice as high as those derived from decay rates calculated locally,says Plumptre."However accurate your dung densityestimate might be,the decay rate can severely affect the result.''Plumptre also says that the dung-pile census should be carried out over a region similar in size to an elephant's natural range.The usual technique of monitoring only small, protected areas distorts numbers because elephants move in and out of these regions,he says."If the elephant population increases within the protected area,you can not determine whether it is a real increase or whether it is due to elephants moving in because they are being poached（入侵偷猎）outside."Plumptre says that similar problems may also affect other animal census studies that rely on indirect evidence such as nests,tracks or burrows（地洞）.Piles of dung can't be relied upon when it comes to estimating elephant numbers becauseA:they are different in size.B:they scatter all over the region.C:they are different in decay rate.D:they are different in quality.
共用题干第二篇Don't Count on Dung（粪便）Conservationists（自然保护主义者）may be miscalculating the numbers of the threatened animals such as elephants,say African and American researchers. The error occurs because of a flaw in the way they estimate animal numbers from the piles of dung（粪）the creatures leave behind.The mistake could lead researchers to think that there are twice as many elephants as there really are in some regions according to Andrew Plumptre of the Wildlife Conservation Society(WCS)in New York.Biologist Katy Payne of Cornell University in Ithaca,New York,agrees,"We really need to know elephant numbers and the evidence that we have is quite indirect,"says Payne,who electronically tracks elephants.Counting elephants from planes is impossible in the vast rainforests of Central Africa. So researchers often estimate elephant numbers by counting dung piles in a given area. They also need to know the rate at which dung decays because it's extremely difficult to determine these rates. However,researchers counting elephants in one region tend to rely on standard decay rates established elsewhere.But researchers at the WCS have found that this decay rate varies from region to region depending on the climate and environment. "Using the wrong values can lead the census astray（离开正道）,"says Plumptre.He and his colleague Anthony Chifu Nchanji studied decaying elephant dung in the forests of Cameroon.They found that the dung decayed between 55 and 65 percent more slowly than the dung in the rainforests of neighbouring Gabon.If researchers use decay rates from Gabon to count elephants in Cameroon,they would probably find more elephants than are actually around.This could mean estimates in Cameroon are at least twice as high as those derived from decay rates calculated locally,says Plumptre"However accurate your dung density estimate might be,the decay rate can severely affect the result."Plumptre also says that the dung-pile census should be carried out over a region similar in size to an elephant's natural range.The usual technique of monitoring only small,protected areas distorts numbers because elephants move in and out of these regions,he says"If the elephant population increases within the protected area,you cannot determine whether it is a real increase or whether it is due to elephants moving in because they are being poached（入侵偷猎）outside."Plumptre says that similar problems may also affect other animal census studies that rely on indirect evidence such as nests,tracks or burrows（地洞）. Piles of dung can't be relied upon when it comes to estimating elephant numbers because______.A:they are different in sizeB:they scatter an over the regionC:they are different in decay rateD:they are different in quality
共用题干第二篇Don't Count on Dung（粪便）Conservationists（自然保护主义者）may be miscalculating the numbers of the threatened animals such as elephants,say African and American researchers. The error occurs because of a flaw in the way they estimate animal numbers from the piles of dung（粪）the creatures leave behind.The mistake could lead researchers to think that there are twice as many elephants as there really are in some regions according to Andrew Plumptre of the Wildlife Conservation Society(WCS)in New York.Biologist Katy Payne of Cornell University in Ithaca,New York,agrees,"We really need to know elephant numbers and the evidence that we have is quite indirect,"says Payne,who electronically tracks elephants.Counting elephants from planes is impossible in the vast rainforests of Central Africa. So researchers often estimate elephant numbers by counting dung piles in a given area. They also need to know the rate at which dung decays because it's extremely difficult to determine these rates. However,researchers counting elephants in one region tend to rely on standard decay rates established elsewhere.But researchers at the WCS have found that this decay rate varies from region to region depending on the climate and environment. "Using the wrong values can lead the census astray（离开正道）,"says Plumptre.He and his colleague Anthony Chifu Nchanji studied decaying elephant dung in the forests of Cameroon.They found that the dung decayed between 55 and 65 percent more slowly than the dung in the rainforests of neighbouring Gabon.If researchers use decay rates from Gabon to count elephants in Cameroon,they would probably find more elephants than are actually around.This could mean estimates in Cameroon are at least twice as high as those derived from decay rates calculated locally,says Plumptre"However accurate your dung density estimate might be,the decay rate can severely affect the result."Plumptre also says that the dung-pile census should be carried out over a region similar in size to an elephant's natural range.The usual technique of monitoring only small,protected areas distorts numbers because elephants move in and out of these regions,he says"If the elephant population increases within the protected area,you cannot determine whether it is a real increase or whether it is due to elephants moving in because they are being poached（入侵偷猎）outside."Plumptre says that similar problems may also affect other animal census studies that rely on indirect evidence such as nests,tracks or burrows（地洞）.According to Plumptre,the region over which a dung-pile census is carried out should be______.A:small enough B:well protectedC:carefully monitored D:large enough
共用题干第二篇Don't Count on Dung（粪便）Conservationists（自然保护主义者）may be miscalculating the numbers of the threatened animals such as elephants,say African and American researchers. The error occurs because of a flaw in the way they estimate animal numbers from the piles of dung（粪）the creatures leave behind.The mistake could lead researchers to think that there are twice as many elephants as there really are in some regions according to Andrew Plumptre of the Wildlife Conservation Society(WCS)in New York.Biologist Katy Payne of Cornell University in Ithaca,New York,agrees,"We really need to know elephant numbers and the evidence that we have is quite indirect,"says Payne,who electronically tracks elephants.Counting elephants from planes is impossible in the vast rainforests of Central Africa. So researchers often estimate elephant numbers by counting dung piles in a given area. They also need to know the rate at which dung decays because it's extremely difficult to determine these rates. However,researchers counting elephants in one region tend to rely on standard decay rates established elsewhere.But researchers at the WCS have found that this decay rate varies from region to region depending on the climate and environment. "Using the wrong values can lead the census astray（离开正道）,"says Plumptre.He and his colleague Anthony Chifu Nchanji studied decaying elephant dung in the forests of Cameroon.They found that the dung decayed between 55 and 65 percent more slowly than the dung in the rainforests of neighbouring Gabon.If researchers use decay rates from Gabon to count elephants in Cameroon,they would probably find more elephants than are actually around.This could mean estimates in Cameroon are at least twice as high as those derived from decay rates calculated locally,says Plumptre"However accurate your dung density estimate might be,the decay rate can severely affect the result."Plumptre also says that the dung-pile census should be carried out over a region similar in size to an elephant's natural range.The usual technique of monitoring only small,protected areas distorts numbers because elephants move in and out of these regions,he says"If the elephant population increases within the protected area,you cannot determine whether it is a real increase or whether it is due to elephants moving in because they are being poached（入侵偷猎）outside."Plumptre says that similar problems may also affect other animal census studies that rely on indirect evidence such as nests,tracks or burrows（地洞）.Why do researchers estimate elephant numbers in an area by counting dung piles?A:Because elephants are difficult to catch.B:Because it is not possible to count elephants from a plane.C:Because it is not possible to keep track of elephants.D:Because elephants are shy anitnals.
共用题干第二篇Don't Count on Dung（粪便）Conservationists（自然保护主义者）may be miscalculating the numbers of the threatened animals such as elephants,say African and American researchers. The error occurs because of a flaw in the way they estimate animal numbers from the piles of dung（粪）the creatures leave behind.The mistake could lead researchers to think that there are twice as many elephants as there really are in some regions according to Andrew Plumptre of the Wildlife Conservation Society(WCS)in New York.Biologist Katy Payne of Cornell University in Ithaca,New York,agrees,"We really need to know elephant numbers and the evidence that we have is quite indirect,"says Payne,who electronically tracks elephants.Counting elephants from planes is impossible in the vast rainforests of Central Africa. So researchers often estimate elephant numbers by counting dung piles in a given area. They also need to know the rate at which dung decays because it's extremely difficult to determine these rates. However,researchers counting elephants in one region tend to rely on standard decay rates established elsewhere.But researchers at the WCS have found that this decay rate varies from region to region depending on the climate and environment. "Using the wrong values can lead the census astray（离开正道）,"says Plumptre.He and his colleague Anthony Chifu Nchanji studied decaying elephant dung in the forests of Cameroon.They found that the dung decayed between 55 and 65 percent more slowly than the dung in the rainforests of neighbouring Gabon.If researchers use decay rates from Gabon to count elephants in Cameroon,they would probably find more elephants than are actually around.This could mean estimates in Cameroon are at least twice as high as those derived from decay rates calculated locally,says Plumptre"However accurate your dung density estimate might be,the decay rate can severely affect the result."Plumptre also says that the dung-pile census should be carried out over a region similar in size to an elephant's natural range.The usual technique of monitoring only small,protected areas distorts numbers because elephants move in and out of these regions,he says"If the elephant population increases within the protected area,you cannot determine whether it is a real increase or whether it is due to elephants moving in because they are being poached（入侵偷猎）outside."Plumptre says that similar problems may also affect other animal census studies that rely on indirect evidence such as nests,tracks or burrows（地洞）.The first word"He"in paragraph 6 refers to______.A:Andrew Plumptre B:Katy PayneC:Anthony Chifu Nchanji D:the writer of the article
问答题A set dominoes(多米诺) consists of rectangular (矩形的) tiles each carrying two numbers from 0 to 6 which represented by patterns of spots. Every possible pairing of numbers occurs just once including each number with itself. How many dominoes are there in a set?