共用题干Older Volcanic EruptionsVolcanoes were more destructive in ancient history,not because they were bigger,but because the carbon dioxide they released wiped out life with greater ease.Paul Wignall from the University of Leeds was investigating the link between volcanic eruptions and mass extinctions.Not all volcanic eruptions killed off large numbers of animals,but all the mass extinctions over the past 300 million years coincided with huge formations of volcanic rock.To his surprise,the older the massive volcanic eruptions were,the more damage they seemed to do.He calculated the"killing efficiency" for these volcanoes by comparing the proportion of life they killed off with the volume of lava（熔岩）that they produced.He found that size for size,older eruptions were at least 10 times as effective at wiping out life as their more recent rivals.The Permian（二叠纪）extinction,for example,which happened 250 million years ago,is marked by floods of volcanic rock in Siberia that cover an area roughly the size of western Europe.Those volcanoes are thought to have pumped out about 10 gigatonnes of carbon as carbon dioxide.The global warming that followed wiped out 80 percent of all marine genera（种类）at the time,and it took 5 million years for the planet to recover.Yet 60 million years ago,there was another huge amount of volcanic activity and global warming but no mass extinction.Some animals did disappear but things returned to normal within ten thousand of years."The most recent ones hardlyhave an effect at all,"Wignall says.He ignored the extinction which wiped out the dinosaurs 65 million years ago,because many scientists believe it was primarily caused by the impact of an asteroid（小行星）.He thinks that older volcanoes had more killing power because more recent life forms were better adapted to dealing with increased levels of CO2．Vincent Courtill.ot,director of the Paris Geophysical Institute in France,says that Wignall's idea is provocative.But he says it is incredibly hard to do these sorts of calculations.He points out that the killing power of volcanic eruptions depends on how long they lasted.And it is impossible to tell whether the huge blasts lasted for tliousands or millions of years.He also adds that it is difficult to estimate how much lava prehistoric volcanoes produced,and that lava volume may not necessarily correspond to carbon dioxide emissions。When did dinosaurs become extinct?A:300 million years ago.B:250 milliOn years ago.C:60 million years ago.D:65 million years ago.
共用题干
Older Volcanic Eruptions
Volcanoes were more destructive in ancient history,not because they were bigger,but because the carbon dioxide they released wiped out life with greater ease.
Paul Wignall from the University of Leeds was investigating the link between volcanic eruptions and mass extinctions.Not all volcanic eruptions killed off large numbers of animals,but all the mass extinctions over the past 300 million years coincided with huge formations of volcanic rock.To his surprise,the older the massive volcanic eruptions were,the more damage they seemed to do.He calculated the"killing efficiency" for these volcanoes by comparing the proportion of life they killed off with the volume of lava（熔岩）that they produced.He found that size for size,older eruptions were at least 10 times as effective at wiping out life as their more recent rivals.
The Permian（二叠纪）extinction,for example,which happened 250 million years ago,is marked by floods of volcanic rock in Siberia that cover an area roughly the size of western Europe.Those volcanoes are thought to have pumped out about 10 gigatonnes of carbon as carbon dioxide.The global warming that followed wiped out 80 percent of all marine genera（种类）at the time,and it took 5 million years for the planet to recover.Yet 60 million years ago,there was another huge amount of volcanic activity and global warming but no mass extinction.Some animals did disappear but things returned to normal within ten thousand of years."The most recent ones hardly
have an effect at all,"Wignall says.He ignored the extinction which wiped out the dinosaurs 65 million years ago,because many scientists believe it was primarily caused by the impact of an asteroid（小行星）.He thinks that older volcanoes had more killing power because more recent life forms were better adapted to dealing with increased levels of CO2．
Vincent Courtill.ot,director of the Paris Geophysical Institute in France,says that Wignall's idea is provocative.But he says it is incredibly hard to do these sorts of calculations.He points out that the killing power of volcanic eruptions depends on how long they lasted.And it is impossible to tell whether the huge blasts lasted for tliousands or millions of years.He also adds that it is difficult to estimate how much lava prehistoric volcanoes produced,and that lava volume may not necessarily correspond to carbon dioxide emissions。
Older Volcanic Eruptions
Volcanoes were more destructive in ancient history,not because they were bigger,but because the carbon dioxide they released wiped out life with greater ease.
Paul Wignall from the University of Leeds was investigating the link between volcanic eruptions and mass extinctions.Not all volcanic eruptions killed off large numbers of animals,but all the mass extinctions over the past 300 million years coincided with huge formations of volcanic rock.To his surprise,the older the massive volcanic eruptions were,the more damage they seemed to do.He calculated the"killing efficiency" for these volcanoes by comparing the proportion of life they killed off with the volume of lava（熔岩）that they produced.He found that size for size,older eruptions were at least 10 times as effective at wiping out life as their more recent rivals.
The Permian（二叠纪）extinction,for example,which happened 250 million years ago,is marked by floods of volcanic rock in Siberia that cover an area roughly the size of western Europe.Those volcanoes are thought to have pumped out about 10 gigatonnes of carbon as carbon dioxide.The global warming that followed wiped out 80 percent of all marine genera（种类）at the time,and it took 5 million years for the planet to recover.Yet 60 million years ago,there was another huge amount of volcanic activity and global warming but no mass extinction.Some animals did disappear but things returned to normal within ten thousand of years."The most recent ones hardly
have an effect at all,"Wignall says.He ignored the extinction which wiped out the dinosaurs 65 million years ago,because many scientists believe it was primarily caused by the impact of an asteroid（小行星）.He thinks that older volcanoes had more killing power because more recent life forms were better adapted to dealing with increased levels of CO2．
Vincent Courtill.ot,director of the Paris Geophysical Institute in France,says that Wignall's idea is provocative.But he says it is incredibly hard to do these sorts of calculations.He points out that the killing power of volcanic eruptions depends on how long they lasted.And it is impossible to tell whether the huge blasts lasted for tliousands or millions of years.He also adds that it is difficult to estimate how much lava prehistoric volcanoes produced,and that lava volume may not necessarily correspond to carbon dioxide emissions。
When did dinosaurs become extinct?
A:300 million years ago.
B:250 milliOn years ago.
C:60 million years ago.
D:65 million years ago.
A:300 million years ago.
B:250 milliOn years ago.
C:60 million years ago.
D:65 million years ago.
参考解析
解析：由文章第一段可知，远古火山喷发更具破坏力，不是因为它们规模更大，而是因为它们释放出的二氧化碳更容易毁灭生命。故选A。
由文章第二段第四句话“He calculated the ‘ killing efficiency ' for those… they are produced.”可知，Wignall通过比较火山释放的熔岩的体积与杀死生命的比例计算这些火山的杀伤力。故选D0
由文章第三段倒数第二句话“He ignored the extinction which wiped out the dinosaurs 65 million years ago …”可知，恐龙是在6500万年前灭绝的。故选D。
由文章第三段倒数第二句话“… because many scientists believe it was primarily caused by the impact of an asteroid.”可知，Wignall没有提6500万年前恐龙的灭绝是否跟火山爆发有关是因为许多科学家认为恐龙的灭绝是由一颗小行星的影响造成的。由此可推断出关于恐龙灭绝的原因在科学家之间是有分歧的。故选D。
文章第一段直接点明了文章的主要论点。" Volcanoes were more destructive in ancient history..."（古代火山喷发更具破坏力）。故选B。
由文章第二段第四句话“He calculated the ‘ killing efficiency ' for those… they are produced.”可知，Wignall通过比较火山释放的熔岩的体积与杀死生命的比例计算这些火山的杀伤力。故选D0
由文章第三段倒数第二句话“He ignored the extinction which wiped out the dinosaurs 65 million years ago …”可知，恐龙是在6500万年前灭绝的。故选D。
由文章第三段倒数第二句话“… because many scientists believe it was primarily caused by the impact of an asteroid.”可知，Wignall没有提6500万年前恐龙的灭绝是否跟火山爆发有关是因为许多科学家认为恐龙的灭绝是由一颗小行星的影响造成的。由此可推断出关于恐龙灭绝的原因在科学家之间是有分歧的。故选D。
文章第一段直接点明了文章的主要论点。" Volcanoes were more destructive in ancient history..."（古代火山喷发更具破坏力）。故选B。
相关考题：
Why did American city residents want to live in the suburbs after World War Ⅱ?A. Because older American cities were dying.B. Because they were richer and needed more space.C. Because cities contained the wont pare of society.D. Because they could hardly afford a live in the city.
Why does author say that they were lucky in the third paragraph?A. Because her situation was not serious.B. Because many other places were flooded.C. Because she had been to Northern India.D. Because some others suffered even more.
The policemen acted quickly because lives were at stake.A:in dangerB:in difficultyC:in despairD:out of control
共用题干第二篇Natural MedicinesSince earliest days,humans have used some kinds of medicines.We know this because humans have survived.Ancient treatments for injury and disease were successful enough to keep humans from dying out completely.They were successful long before the time of modern medicine.Before the time of doctors with white coats and shiny（发亮的）instruments. Before the time of big hospitals with strange and wonderful equipment.Many parts of the world still do not have university-educated doctors. Nor do they have expensive hospi- tals.Yet injuries are treated.And diseases are often cured.How?By ancient methods.By medicines that might seem mysterious , even magical（有魔力的）.Traditional medicines are neither mysterious nor magical, however.Through the centuries, tribal（部族的）medicine men experimented with plants. They found many use- ful chemicals in the plants.And scientists believe many of these traditional medicines may provide the cure for some of today's most serious diseases.Experts say almost 80% of the people in the world use plants for health care.These natural medicines are used not just because people have no other form of treatment.They are used because people trust them. In developed areas,few people think about the source of the medicines they buy in a store.Yet many wide- ly-used medicines are from ancient sources,especially plants.Some experts say more than 25% of modern medicines come,in one way or another,from nature.Scientists have long known that nature is really a chemical factory.All living things contain chemicals that help them survive.So scientists' interest in traditional medicine is not new.But it has become an ur-gent concern.This is because the earth's supply of natural medicines may be dropping rapidly. The passage indicates that ancient treatments for injury and disease were_________.A:much more successful than modern onesB:successful enough for humans to surviveC:successful in all casesD:of little help to humans
共用题干Egypt Felled by FamineEven ancient Egypt's mighty pyramid builders were powerless in the face of the famine that helped bring down their civilization around 2180 BC.Now evidence gleaned（搜集）from mud deposited by the River Nile suggests that a shift in climate thousands of kilometers to the south was ultimately to blame-and the same or worse could happen today.The ancient Egyptians depended on the Nile's annual floods to irrigate their crops.But any change in climate that pushed the African monsoons（季风）southwards out of Ethiopia would have diminished these floods.Dwindling（使减少）rains in the Ethiopian highlands would have meant fewer plants to establish the soil.When rain did fall it would have washed large amounts of soil into the Blue Nile and into Egypt,along with sediment（沉积物）from the White Nile.The Blue Nile mud has a different isotope（同位素）signature from that of the White Nile.So by analyzing isotope differences in mud deposited in the Nile Delta,Michael Krom of Leeds University worked out what proportion of sediment came from each branch of the river.Krom reasons that during periods of drought,the amount of the Blue Nile mud in the river would be relatively high.He found that one of these periods,from 4,500 to 4,200 years ago,immediately predated the fall of the Egypt's old Kingdom.The weakened waters would have been catastrophic for the Egyptians."Changes that affect food supply don't have to be very large to have a ripple effect in societies,"says Bill Ryan of the Lamont Doherty Earth Observatory（天文台）in New York."Similar events today coald be even more devastating,"says team member Daniel Stanley,a geoarchaeologist from the Smithsonian Institution in Washington, D.0."Anything humans do to shift the climate belts woulld have an even worse effect along the Nile system because the populations have increased dramatically."Why does the author mention"pyramid builders"?A:Because they once worked miracles.B:Because they were well-built.C:Because they were actually very weak.D:Because even they were unable to rescue their civilization.
共用题干Older Volcanic EruptionsVolcanoes were more destructive in ancient history,not because they were bigger,but because the carbon dioxide they released wiped out life with greater ease.Paul Wignall from the University of Leeds was investigating the link between volcanic eruptions and mass extinctions.Not all volcanic eruptions killed off large numbers of animals,but all the mass extinctions over the past 300 million years coincided with huge formations of volcanic rock.To his surprise,the older the massive.volcanic eruptions were,the more damage they seemed to do.He calculated the"killing efficiency" for these volcanoes by comparing the proportion of life they killed off with the volume of lava（熔岩）that they produced.He found that size for size,older eruptions were at least 10 times as effective at wiping out life as their more recent rivals.The Permian（二叠纪）extinction,for example,which happened 250 million years ago,is marked by floods of volcanic rock in Siberia that cover an area roughly the size of western Europe.Those volcanoes are thought to have pumped out about 1 0 gigatonnes（十亿吨）of carbon as carbon dioxide.The global warming that followed wiped out 80 percent of all marine genera（种类）at the time,and it took 5 million years for the planet to recover.Yet 60 million years ago,there was another huge amount of volcanic activity and global warming but no mass extinction.Some animals did disappear but things returned to normal within ten thousands of years."The most recent ones hardly have an effect at all,"Wignall says.He ignored the extinction which wiped out the dinosaurs 65 million years ago,because many scientists believe it was primarily caused by the impact of an asteroid（小行星）.He thinks that older volcanoes had more killing power because more recent life forms were better adapted to dealing with increased levels of CO2.Vincent Courtillot,director of the Paris Geophysical InstitUte in France,says that Wignall's idea is provoca- tive.But he says it is incredibly hard to do these sorts of calculations.He points out that the killing power of volcanic eruptions depends on how long they lasted.And it is impossible to tell whether the huge blasts lasted for thousands or millions of years.He also adds that it is difficult to estimate how much lava prehistoric volcanoes produced,and that lava volume may not necessarily correspond to carbon dioxide emissions.Which of the following is wrong according to Paragraph 3?A:Only 80 percent of marine genera survived the global warming caused by the Permian extinction.B:It took 5 million years for the planet to recover from the Permian extinction.C:The huge amount of volcanic activity and乡obal warming 60 million years ago did not lead to mass extinction.D:The cause of dinosaurs'extinction has remained a controversial issue.
共用题干Natural MedicinesSince earliest days,humans have used some kinds of medicines.We know this because hu-mans have survived .Ancient treatments for injury and disease were successful enough to keep hu-mans from dying out completely.They were successful long before the time of modern medicine.Before the time of doctors with white coats and shiny（发亮的）instruments. Before the time of big hospitals with strange and wonderful equipment.Many parts of the world still do not have university-educated doctors.Nor do they have ex- pensive hospitals.Yet injuries are treated.And diseases are often cured.How?By ancient meth- ods. By medicines that might seem mysterious, even magical（有魔力的）.Traditional medicines are neither mysterious nor magical,however.Through the centuries, tribal（部落的）medicine men experimented with plants. They found many useful chemicals in the plants.And scientists believe many of these traditional medicines may provide the cure for some of today's most serious diseases.Experts say almost 80%of the people in the world use plants for health care.These natural medicines are used not just because people have no other form of treatment.They are used be-cause people trust them.In developed areas,few people think about the source of the medicines they buy in a store.Yet many widely-used medicines are from ancient sources,especially plants. Some experts say more than 25%of modern medicines come,in one way or another,from nature.Scientists have long known that nature is really a chemical factory.All living things contain chemicals that help them survive .So scientists' interest in traditional medicine is not new.But it has become an urgent concern.This is because the earth's supply of natural medicines may be dropping rapidly. The passage indicates that ancient treatments for injury and disease were_____.A: much more successful than modern onesB: successful enough for humans to surviveC: successful in all casesD: of little help to humans
The firemen acted quickly because lives were at stake.A:in dangerB:in despairC:out of condition D:out of danger
共用题干第一篇Plant GasScientists have been studying natural sources of methane（甲烷，沼气）for decades but hadn't regarded plants as a producer, notes Frank Keppler, a geochemist（地球化学家）at the Max Planck Institute for Nuclear Physics in Heldelberg,Germany. Now Keppler and his colleagues find that plants,from grasses to trees,may also be sources of the greenhouse gas.This is really surprising, because most scientists assumed that methane production requires an oxygen-free environment.Previously,researchers had thought that it was impossible for plants to make significant amounts of the gas. They had assumed that microbes（微生物）need to be in environments without oxygen to produce methane.Methane is a greenhouse gas, like carbon dioxide.Gases such as methane and carbon dioxide trap heat in Earth's atmosphere and contribute to global warming.In its experiments, Keppler's team used sealed chambers（室，房间；腔）that contained the same concentration of oxygen that Earth's atmosphere has.They measured the amounts of methane that were released by both living plants and dried plant material,such as fallen leaves.With the dried plants,the researchers took measurement at temperatures ranging from 30 degrees Celsius to 70 degrees C.At 30 degrees C.,they found,a gram of dried plant material released up to 3 nanograms（微克）of methane per hour(One nanogram is a millionth of a gram). With every 10-degree rise in temperature,the amount of methane released each hour roughly doubled.Living plants growing at their normal temperatures released as much as 370 nanograms of methane per gram of plant tissue per hour. Methane emissions tripled when living and dead plant was exposed to sunlight.Because there was plenty of oxygen available,it's unlikely that the types of bacteria(bacterium的复数，细菌）that normally make methane were involved. Experiments on plants that were grown in water rather than soil also resulted in methane emissions.That's another strong sign that the gas came from the plants and not soil microbes.The new finding is an"interesting observation,"says Jennifer Y. King,a biogeochemist（生物地球化学家）at the University of Minnesota in St. Paul. Because some types of soil microbes consume methane,they may prevent plant-produced methane from reaching the atmosphere.Field tests will be needed to assess the plant's influence,she notes.What was scientists' understanding of methane?A:It was produced from plants.B:It was not a greenhouse gas.C:It was produced in oxygen-free environments.D:It traps more heat than any other greenhouse gas.
共用题干第一篇Plant GasScientists have been studying natural sources of methane（甲烷，沼气）for decades but hadn't regarded plants as a producer, notes Frank Keppler, a geochemist（地球化学家）at the Max Planck Institute for Nuclear Physics in Heldelberg,Germany. Now Keppler and his colleagues find that plants,from grasses to trees,may also be sources of the greenhouse gas.This is really surprising, because most scientists assumed that methane production requires an oxygen-free environment.Previously,researchers had thought that it was impossible for plants to make significant amounts of the gas. They had assumed that microbes（微生物）need to be in environments without oxygen to produce methane.Methane is a greenhouse gas, like carbon dioxide.Gases such as methane and carbon dioxide trap heat in Earth's atmosphere and contribute to global warming.In its experiments, Keppler's team used sealed chambers（室，房间；腔）that contained the same concentration of oxygen that Earth's atmosphere has.They measured the amounts of methane that were released by both living plants and dried plant material,such as fallen leaves.With the dried plants,the researchers took measurement at temperatures ranging from 30 degrees Celsius to 70 degrees C.At 30 degrees C.,they found,a gram of dried plant material released up to 3 nanograms（微克）of methane per hour(One nanogram is a millionth of a gram). With every 10-degree rise in temperature,the amount of methane released each hour roughly doubled.Living plants growing at their normal temperatures released as much as 370 nanograms of methane per gram of plant tissue per hour. Methane emissions tripled when living and dead plant was exposed to sunlight.Because there was plenty of oxygen available,it's unlikely that the types of bacteria(bacterium的复数，细菌）that normally make methane were involved. Experiments on plants that were grown in water rather than soil also resulted in methane emissions.That's another strong sign that the gas came from the plants and not soil microbes.The new finding is an"interesting observation,"says Jennifer Y. King,a biogeochemist（生物地球化学家）at the University of Minnesota in St. Paul. Because some types of soil microbes consume methane,they may prevent plant-produced methane from reaching the atmosphere.Field tests will be needed to assess the plant's influence,she notes.Which statement is true of the methane emissions of plants in the experiment?A:The lower the temperature,the higher the amount of methane emissions.B:Living plants release less methane than dried plants at the same temperature.C:When exposed to sunlight,plants stop releasing methane.D:The higher the temperature,the greater the amount of methane emissions.
共用题干第一篇Plant GasScientists have been studying natural sources of methane（甲烷，沼气）for decades but hadn't regarded plants as a producer, notes Frank Keppler, a geochemist（地球化学家）at the Max Planck Institute for Nuclear Physics in Heldelberg,Germany. Now Keppler and his colleagues find that plants,from grasses to trees,may also be sources of the greenhouse gas.This is really surprising, because most scientists assumed that methane production requires an oxygen-free environment.Previously,researchers had thought that it was impossible for plants to make significant amounts of the gas. They had assumed that microbes（微生物）need to be in environments without oxygen to produce methane.Methane is a greenhouse gas, like carbon dioxide.Gases such as methane and carbon dioxide trap heat in Earth's atmosphere and contribute to global warming.In its experiments, Keppler's team used sealed chambers（室，房间；腔）that contained the same concentration of oxygen that Earth's atmosphere has.They measured the amounts of methane that were released by both living plants and dried plant material,such as fallen leaves.With the dried plants,the researchers took measurement at temperatures ranging from 30 degrees Celsius to 70 degrees C.At 30 degrees C.,they found,a gram of dried plant material released up to 3 nanograms（微克）of methane per hour(One nanogram is a millionth of a gram). With every 10-degree rise in temperature,the amount of methane released each hour roughly doubled.Living plants growing at their normal temperatures released as much as 370 nanograms of methane per gram of plant tissue per hour. Methane emissions tripled when living and dead plant was exposed to sunlight.Because there was plenty of oxygen available,it's unlikely that the types of bacteria(bacterium的复数，细菌）that normally make methane were involved. Experiments on plants that were grown in water rather than soil also resulted in methane emissions.That's another strong sign that the gas came from the plants and not soil microbes.The new finding is an"interesting observation,"says Jennifer Y. King,a biogeochemist（生物地球化学家）at the University of Minnesota in St. Paul. Because some types of soil microbes consume methane,they may prevent plant-produced methane from reaching the atmosphere.Field tests will be needed to assess the plant's influence,she notes.To test whether plants are a source of methane,the scientists created_______.A:an oxygen-free environmentB:an environment with the same concentration of oxygen as the Earth hasC:a carbon dioxide-free environmentD:an environment filled with the greenhouse gas
共用题干Older Volcanic EruptionsVolcanoes were more destructive in ancient history,not because they were bigger,but because the carbon dioxide they released wiped out life with greater ease.Paul Wignall from the University of Leeds was investigating the link between volcanic eruptions and mass extinctions.Not all volcanic eruptions killed off large numbers of animals,but all the mass extinctions over the past 300 million years coincided with huge formations of volcanic rock.To his surprise,the older the massive volcanic eruptions were,the more damage they seemed to do.He calculated the"killing efficiency" for these volcanoes by comparing the proportion of life they killed off with the volume of lava（熔岩）that they produced.He found that size for size,older eruptions were at least 10 times as effective at wiping out life as their more recent rivals.The Permian（二叠纪）extinction,for example,which happened 250 million years ago,is marked by floods of volcanic rock in Siberia that cover an area roughly the size of western Europe.Those volcanoes are thought to have pumped out about 10 gigatonnes of carbon as carbon dioxide.The global warming that followed wiped out 80 percent of all marine genera（种类）at the time,and it took 5 million years for the planet to recover.Yet 60 million years ago,there was another huge amount of volcanic activity and global warming but no mass extinction.Some animals did disappear but things returned to normal within ten thousand of years."The most recent ones hardlyhave an effect at all,"Wignall says.He ignored the extinction which wiped out the dinosaurs 65 million years ago,because many scientists believe it was primarily caused by the impact of an asteroid（小行星）.He thinks that older volcanoes had more killing power because more recent life forms were better adapted to dealing with increased levels of CO2．Vincent Courtill.ot,director of the Paris Geophysical Institute in France,says that Wignall's idea is provocative.But he says it is incredibly hard to do these sorts of calculations.He points out that the killing power of volcanic eruptions depends on how long they lasted.And it is impossible to tell whether the huge blasts lasted for tliousands or millions of years.He also adds that it is difficult to estimate how much lava prehistoric volcanoes produced,and that lava volume may not necessarily correspond to carbon dioxide emissions。Why did older volcanic eruptions do more damage than more recent ones?A:Because they killed off life more easily.B:Because they were brighter.C:Because they were larger.D:Because they were hotter.
共用题干Older Volcanic EruptionsVolcanoes were more destructive in ancient history,not because they were bigger,but because the carbon dioxide they released wiped out life with greater ease.Paul Wignall from the University of Leeds was investigating the link between volcanic eruptions and mass extinctions.Not all volcanic eruptions killed off large numbers of animals,but all the mass extinctions over the past 300 million years coincided with huge formations of volcanic rock.To his surprise,the older the massive volcanic eruptions were,the more damage they seemed to do.He calculated the"killing efficiency" for these volcanoes by comparing the proportion of life they killed off with the volume of lava（熔岩）that they produced.He found that size for size,older eruptions were at least 10 times as effective at wiping out life as their more recent rivals.The Permian（二叠纪）extinction,for example,which happened 250 million years ago,is marked by floods of volcanic rock in Siberia that cover an area roughly the size of western Europe.Those volcanoes are thought to have pumped out about 10 gigatonnes of carbon as carbon dioxide.The global warming that followed wiped out 80 percent of all marine genera（种类）at the time,and it took 5 million years for the planet to recover.Yet 60 million years ago,there was another huge amount of volcanic activity and global warming but no mass extinction.Some animals did disappear but things returned to normal within ten thousand of years."The most recent ones hardlyhave an effect at all,"Wignall says.He ignored the extinction which wiped out the dinosaurs 65 million years ago,because many scientists believe it was primarily caused by the impact of an asteroid（小行星）.He thinks that older volcanoes had more killing power because more recent life forms were better adapted to dealing with increased levels of CO2．Vincent Courtill.ot,director of the Paris Geophysical Institute in France,says that Wignall's idea is provocative.But he says it is incredibly hard to do these sorts of calculations.He points out that the killing power of volcanic eruptions depends on how long they lasted.And it is impossible to tell whether the huge blasts lasted for tliousands or millions of years.He also adds that it is difficult to estimate how much lava prehistoric volcanoes produced,and that lava volume may not necessarily correspond to carbon dioxide emissions。What can be inferred from Paragraph 3 concerning dinosaurs?A:They were killed off by an asteroid.B:They died of drastic climate change.C:They were wiped off by a volcanic eruption.D:The cause of their extinction has remained a controversial issue.
共用题干Older Volcanic EruptionsVolcanoes were more destructive in ancient history,not because they were bigger,but because the carbon dioxide they released wiped out life with greater ease.Paul Wignall from the University of Leeds was investigating the link between volcanic eruptions and mass extinctions.Not all volcanic eruptions killed off large numbers of animals,but all the mass extinctions over the past 300 million years coincided with huge formations of volcanic rock.To his surprise,the older the massive volcanic eruptions were,the more damage they seemed to do.He calculated the"killing efficiency" for these volcanoes by comparing the proportion of life they killed off with the volume of lava（熔岩）that they produced.He found that size for size,older eruptions were at least 10 times as effective at wiping out life as their more recent rivals.The Permian（二叠纪）extinction,for example,which happened 250 million years ago,is marked by floods of volcanic rock in Siberia that cover an area roughly the size of western Europe.Those volcanoes are thought to have pumped out about 10 gigatonnes of carbon as carbon dioxide.The global warming that followed wiped out 80 percent of all marine genera（种类）at the time,and it took 5 million years for the planet to recover.Yet 60 million years ago,there was another huge amount of volcanic activity and global warming but no mass extinction.Some animals did disappear but things returned to normal within ten thousand of years."The most recent ones hardlyhave an effect at all,"Wignall says.He ignored the extinction which wiped out the dinosaurs 65 million years ago,because many scientists believe it was primarily caused by the impact of an asteroid（小行星）.He thinks that older volcanoes had more killing power because more recent life forms were better adapted to dealing with increased levels of CO2．Vincent Courtill.ot,director of the Paris Geophysical Institute in France,says that Wignall's idea is provocative.But he says it is incredibly hard to do these sorts of calculations.He points out that the killing power of volcanic eruptions depends on how long they lasted.And it is impossible to tell whether the huge blasts lasted for tliousands or millions of years.He also adds that it is difficult to estimate how much lava prehistoric volcanoes produced,and that lava volume may not necessarily correspond to carbon dioxide emissions。How did Wignall calculate the killing power of those older volcanic eruptions?A:By estimating how long they lasted.B:By counting the dinosaurs they killed.C:By studying the chemical composition of lava.D:By comparing the proportion of life wiped out with the volume of lava produced.
共用题干Older Volcanic EruptionsVolcanoes were more destructive in ancient history,not because they were bigger,but because the carbon dioxide they released wiped out life with greater ease.Paul Wignall from the University of Leeds was investigating the link between volcanic eruptions and mass extinctions.Not all volcanic eruptions killed off large numbers of animals,but all the mass extinctions over the past 300 million years coincided with huge formations of volcanic rock.To his surprise,the older the massive volcanic eruptions were,the more damage they seemed to do.He calculated the"killing efficiency" for these volcanoes by comparing the proportion of life they killed off with the volume of lava（熔岩）that they produced.He found that size for size,older eruptions were at least 10 times as effective at wiping out life as their more recent rivals.The Permian（二叠纪）extinction,for example,which happened 250 million years ago,is marked by floods of volcanic rock in Siberia that cover an area roughly the size of western Europe.Those volcanoes are thought to have pumped out about 10 gigatonnes of carbon as carbon dioxide.The global warming that followed wiped out 80 percent of all marine genera（种类）at the time,and it took 5 million years for the planet to recover.Yet 60 million years ago,there was another huge amount of volcanic activity and global warming but no mass extinction.Some animals did disappear but things returned to normal within ten thousand of years."The most recent ones hardlyhave an effect at all,"Wignall says.He ignored the extinction which wiped out the dinosaurs 65 million years ago,because many scientists believe it was primarily caused by the impact of an asteroid（小行星）.He thinks that older volcanoes had more killing power because more recent life forms were better adapted to dealing with increased levels of CO2．Vincent Courtill.ot,director of the Paris Geophysical Institute in France,says that Wignall's idea is provocative.But he says it is incredibly hard to do these sorts of calculations.He points out that the killing power of volcanic eruptions depends on how long they lasted.And it is impossible to tell whether the huge blasts lasted for tliousands or millions of years.He also adds that it is difficult to estimate how much lava prehistoric volcanoes produced,and that lava volume may not necessarily correspond to carbon dioxide emissions。What is the main thesis of the article?A:Volcanic eruptions are riot always deadly.B:Older volcanic eruptions are more destructive.C:Carbon dioxide emissions often give rise to global warming.D:It is not easy to calculate the killing power of a volcanic eruption.
共用题干Natural MedicinesSince earliest days,humans have used some kinds of medicines.We know this because humans have survived.Ancient treatments for injury and disease were successful enough to keep humans from dying out completely.They were successful long before the time of modern medicine. Before the time of doctors with white coats and shiny（发亮的）instruments. Before the time of big hospitals with strange and wonderful equipment.Many parts of the world still do not have university-educated doctors. Nor do they have expensive hospitals.Yet injuries are treated.And diseases are often cured.How?By ancient methods. By medicines that might seem mysterious , even magical（有魔力的）.Traditional medicines are neither mysterious nor magical,however.Through the centuries , tribal（部落的）medicine men experimented with plants. They found many useful chemicals in the plants.And scientists believe many of these traditional medicines may provide the cure for some of today's most serious diseases.Experts say almost 80% of the people in the world use plants for health care.These natural medicines are used not just because people have no other form of treatment. They are used because people trust them. In developed areas,few people think about the source of the medicines they buy in a store .Yet many widely-used medicines are from ancient sources,especially plants.Some experts say more than 25%of modem medicines come,in one way or another,from nature.Scientists have long known that nature is really a chemical factory. All living things contain chemicals that help them survive .So scientists' interest in traditional medicine is not new.But it has become an urgent concern.This is because the earth's supply of natural medicines may be dropping rapidly. The passage indicates that ancient treatments for injury and disease wereA: much more successful than modem onesB: successful enough for humans to surviveC: successful in all casesD: of little help to humans
共用题干Older Volcanic EruptionsVolcanoes were more destructive in ancient history,not because they were bigger,but because the carbon dioxide they released wiped out life with greater ease.Paul Wignall from the University of Leeds was investigating the link between volcanic eruptions and mass extinctions.Not all volcanic eruptions killed off large numbers of animals,but all the mass extinctions over the past 300 million years coincided with huge formations of volcanic rock.To his surprise,the older the massive volcanic eruptions were,the more damage they seemed to do.He calculated the"killing efficiency"for these volcanoes by comparing the proportion of life they killed off with the volume of lava（熔 岩）that they produced.He found that size for size,older eruptions were at least 10 times as effective at wiping out life as their more recent rivals.The Peimian（二叠纪）extinction,for example,which happened 250 million years ago,is marked by floods of volcanic rock in Siberia that cover an area roughly the size of western Europe.Those volcanoes are thought to have pumped out about 10 gigatonnes（十亿吨）of carbon as carbon dioxide.The global warming that followed wiped out 80 prcent of all marine genera（种类）at the time , and it took 5 million years for the planet to recover.Yet 60 million years ago,there was another huge amount of volcanic activity and global warming but no mass extinction.Some animals did disappear but things returned to normal within ten thousands of years."The most recent ones hardly have an effect at all."Wignall says.He ignored the extinction which wiped out the dinosaurs 65 million years ago,because many scientists believe it was primarily caused by the impact of an asteroid（小行星）.He thinks that older volcanoes had more killing power because more recent life forms were better adapted to dealing with increased levels of CO2.Vincent Courtillot,director of the Paris Geophysical Institute in France,says that Wignall's idea is provocative.But he says it is incredibly hard to do these sorts of calculations.He points out that the killing power of volcanic eruptions depends on how long they lasted.And it is impossible to tell whether the huge blasts lasted for thousands or millions of years.He also adds that it is difficult to estimate how much lava prehistoric volcanoes produced,and that lava volume may not necessarily correspond to carbon dioxide emissions."Killing efficiency"is calculated by comparing______.A:the span of time volcanoes lastedB:the volume of lava volcanoes producedC:the number of living things volcanoes killed offD:the proportion of life wiped out with the volume of lava
共用题干Older Volcanic EruptionsVolcanoes were more destructive in ancient history,not because they were bigger,but because the carbon dioxide they released wiped out life with greater ease.Paul Wignall from the University of Leeds was investigating the link between volcanic eruptions and mass extinctions.Not all volcanic eruptions killed off large numbers of animals,but all the mass extinctions over the past 300 million years coincided with huge formations of volcanic rock.To his surprise,the older the massive volcanic eruptions were,the more damage they seemed to do.He calculated the"killing efficiency"for these volcanoes by comparing the proportion of life they killed off with the volume of lava（熔 岩）that they produced.He found that size for size,older eruptions were at least 10 times as effective at wiping out life as their more recent rivals.The Peimian（二叠纪）extinction,for example,which happened 250 million years ago,is marked by floods of volcanic rock in Siberia that cover an area roughly the size of western Europe.Those volcanoes are thought to have pumped out about 10 gigatonnes（十亿吨）of carbon as carbon dioxide.The global warming that followed wiped out 80 prcent of all marine genera（种类）at the time , and it took 5 million years for the planet to recover.Yet 60 million years ago,there was another huge amount of volcanic activity and global warming but no mass extinction.Some animals did disappear but things returned to normal within ten thousands of years."The most recent ones hardly have an effect at all."Wignall says.He ignored the extinction which wiped out the dinosaurs 65 million years ago,because many scientists believe it was primarily caused by the impact of an asteroid（小行星）.He thinks that older volcanoes had more killing power because more recent life forms were better adapted to dealing with increased levels of CO2.Vincent Courtillot,director of the Paris Geophysical Institute in France,says that Wignall's idea is provocative.But he says it is incredibly hard to do these sorts of calculations.He points out that the killing power of volcanic eruptions depends on how long they lasted.And it is impossible to tell whether the huge blasts lasted for thousands or millions of years.He also adds that it is difficult to estimate how much lava prehistoric volcanoes produced,and that lava volume may not necessarily correspond to carbon dioxide emissions.Why were older volcanic eruptions more destructive than more recent ones according to Wignall?A:Because they were brighter.B:Because they were larger.C:Because more recent life forms were better adapted to CO2.D:Because older volcanic eruptions released more lava.
共用题干第一篇The Relationship between IQ and Being a VegetarianA Southampton University team found that people who were vegetarians (素食主义者）by 30 had recor-ded five IQ points higher on average at the age of]U.Researchers said it could explain why people with a higher IQ were healthier as a vegetarian diet was linked to lower heart disease and obesity（肥胖）rates.The study of 8,179 people was reported in the british Medical Journal.Twenty years after the IQ tests were carried out in 1970,366 of the participants said they were vegetarians一 although more than 100 reported eating either fish or chicken.Men who were vegetarians had an IQ score of 106,compared with 101 for non-vegetarians;while female vegetarians averaged 104,compared with 99 for non-vegetarians.There was no difference in the IQ scores between strict vegetarians and those who said they were vegetarians but reported eating fish or chicken.Researchers said the findings were partly related to better education and higher class,but it remained statistically significant after adjusting for these factors.Vegetarians were more likely to be female,to be of higher social class and to have higher academic or vocational qualifications than non-vegetarians.However,these differenIces were not reflected in their annual income,which was similar to that of non-vegetarians.Lead researcher Catharine Gale said,"The findings that children with greater intelligence are more likely to report being vegetarians as adults,together with the evidence on the potential benefits of a vegetarian diet on heart health,may help to explain why a higher IQ in childhood or adolescence is linked with a reduced risk ofcoronary heart disease in adult life."But Dr Frankie Phillips of the British Dietetic Association said, "It is like the chicken and egg."Dopcople become vegetarians because they have avery high IQ or is it just that they are clever enough to bemore aware of health issues?It was found in the research that______________.A:most of the participants became vegetarians 20 years after the IQ tests were carried out B:vegetarians who ate fish or chicken were of similar intelligence with strict vegetariansC:female vegetarians were more likely to have higher annual income than non-vegetariansD:vegetarians were more likely to have higher annual income than non-vegetarians
共用题干Older Volcanic EruptionsVolcanoes were more destructive in ancient history,not because they were bigger,but because the carbon dioxide they released wiped out life with greater ease.Paul Wignall from the University of Leeds was investigating the link between volcanic eruptions and mass extinctions.Not all volcanic eruptions killed off large numbers of animals,but all the mass extinctions over the past 300 million years coincided with huge formations of volcanic rock.To his surprise,the older the massive volcanic eruptions were,the more damage they seemed to do.He calculated the"killing efficiency"for these volcanoes by comparing the proportion of life they killed off with the volume of lava（熔 岩）that they produced.He found that size for size,older eruptions were at least 10 times as effective at wiping out life as their more recent rivals.The Peimian（二叠纪）extinction,for example,which happened 250 million years ago,is marked by floods of volcanic rock in Siberia that cover an area roughly the size of western Europe.Those volcanoes are thought to have pumped out about 10 gigatonnes（十亿吨）of carbon as carbon dioxide.The global warming that followed wiped out 80 prcent of all marine genera（种类）at the time , and it took 5 million years for the planet to recover.Yet 60 million years ago,there was another huge amount of volcanic activity and global warming but no mass extinction.Some animals did disappear but things returned to normal within ten thousands of years."The most recent ones hardly have an effect at all."Wignall says.He ignored the extinction which wiped out the dinosaurs 65 million years ago,because many scientists believe it was primarily caused by the impact of an asteroid（小行星）.He thinks that older volcanoes had more killing power because more recent life forms were better adapted to dealing with increased levels of CO2.Vincent Courtillot,director of the Paris Geophysical Institute in France,says that Wignall's idea is provocative.But he says it is incredibly hard to do these sorts of calculations.He points out that the killing power of volcanic eruptions depends on how long they lasted.And it is impossible to tell whether the huge blasts lasted for thousands or millions of years.He also adds that it is difficult to estimate how much lava prehistoric volcanoes produced,and that lava volume may not necessarily correspond to carbon dioxide emissions.Which of the following is NOT true according to Paragraph 3?A:Only 80 percent of marine genera survived the global warming caused by the Permian extinction.B:It took 5 million years for the planet to recover from the Permian extinction.C:The huge amount of volcathc activity and global warming & million years ago, did not lead to mass extinction.D:The cause of dinosaurs'extinction has remained a controversial issue.
共用题干Older Volcanic EruptionsVolcanoes were more destructive in ancient history,not because they were bigger,but because the carbon dioxide they released wiped out life with greater ease.Paul Wignall from the University of Leeds was investigating the link between volcanic eruptions and mass extinctions.Not all volcanic eruptions killed off large numbers of animals,but all the mass extinctions over the past 300 million years coincided with huge formations of volcanic rock.To his surprise,the older the massive volcanic eruptions were,the more damage they seemed to do.He calculated the"killing efficiency"for these volcanoes by comparing the proportion of life they killed off with the volume of lava（熔 岩）that they produced.He found that size for size,older eruptions were at least 10 times as effective at wiping out life as their more recent rivals.The Peimian（二叠纪）extinction,for example,which happened 250 million years ago,is marked by floods of volcanic rock in Siberia that cover an area roughly the size of western Europe.Those volcanoes are thought to have pumped out about 10 gigatonnes（十亿吨）of carbon as carbon dioxide.The global warming that followed wiped out 80 prcent of all marine genera（种类）at the time , and it took 5 million years for the planet to recover.Yet 60 million years ago,there was another huge amount of volcanic activity and global warming but no mass extinction.Some animals did disappear but things returned to normal within ten thousands of years."The most recent ones hardly have an effect at all."Wignall says.He ignored the extinction which wiped out the dinosaurs 65 million years ago,because many scientists believe it was primarily caused by the impact of an asteroid（小行星）.He thinks that older volcanoes had more killing power because more recent life forms were better adapted to dealing with increased levels of CO2.Vincent Courtillot,director of the Paris Geophysical Institute in France,says that Wignall's idea is provocative.But he says it is incredibly hard to do these sorts of calculations.He points out that the killing power of volcanic eruptions depends on how long they lasted.And it is impossible to tell whether the huge blasts lasted for thousands or millions of years.He also adds that it is difficult to estimate how much lava prehistoric volcanoes produced,and that lava volume may not necessarily correspond to carbon dioxide emissions.What is Vincent Courtillot's attitude towards Wignall's idea?A:Positive. B:Negative.C:Neutral. D:Unclear.
共用题干第一篇The Relationship between IQ and Being a VegetarianA Southampton University team found that people who were vegetarians (素食主义者）by 30 had recor-ded five IQ points higher on average at the age of]U.Researchers said it could explain why people with a higher IQ were healthier as a vegetarian diet was linked to lower heart disease and obesity（肥胖）rates.The study of 8,179 people was reported in the british Medical Journal.Twenty years after the IQ tests were carried out in 1970,366 of the participants said they were vegetarians一 although more than 100 reported eating either fish or chicken.Men who were vegetarians had an IQ score of 106,compared with 101 for non-vegetarians;while female vegetarians averaged 104,compared with 99 for non-vegetarians.There was no difference in the IQ scores between strict vegetarians and those who said they were vegetarians but reported eating fish or chicken.Researchers said the findings were partly related to better education and higher class,but it remained statistically significant after adjusting for these factors.Vegetarians were more likely to be female,to be of higher social class and to have higher academic or vocational qualifications than non-vegetarians.However,these differenIces were not reflected in their annual income,which was similar to that of non-vegetarians.Lead researcher Catharine Gale said,"The findings that children with greater intelligence are more likely to report being vegetarians as adults,together with the evidence on the potential benefits of a vegetarian diet on heart health,may help to explain why a higher IQ in childhood or adolescence is linked with a reduced risk ofcoronary heart disease in adult life."But Dr Frankie Phillips of the British Dietetic Association said, "It is like the chicken and egg."Dopcople become vegetarians because they have avery high IQ or is it just that they are clever enough to bemore aware of health issues?What's the result of the research mentioned in the text?A:Intelligent children are more likely to become vegetarians later in life.B:Children with a higher IQ are less likely to have heart disease later in life.C:Intelligent children tend to belong to higher social class later in life.D:Children with a healthier heart tend to have a higher IQ later in life.
共用题干第二篇Ancient Egypt Brought Down by FamineEven ancient Egypt's mighty pyramid（金字塔）builders were powerless in the face of the famine（饥荒）that helped bring down their civilization around 2180 BC.Now evidencecollected from mud deposited by the River Nile suggests that a shift in climate thousands of kilometers to the south was ultimately to blame一and the same or worse could happen today.The ancient Egyptians depended on the Nile's annual floods to irrigate their crops.But any change in climate that pushed the African monsoons（季风）southwards out of Ethiopia would have reduced these floods.Declining rains in the Ethiopian highlands would have meant fewer plants to stabilize the soil.When rain did fall it would have washed large amounts of soil into the Blue Nile and into Egypt,along with sediment（沉积）from the White Nile.Blue Nile mud has a different isotope（同位素）signature from that of the White Nile.So by analyzing isotope differences in mud deposited in the Nile Delta,Michael Krom of Leeds University worked out what proportion of sediment came from each branch of the river.Krom reasons that during periods of drought,the amount of Blue Nile mud in the river would be relatively high.He found that one of these periods,from 4500 to 4200 years ago, immediately came before the fall of the Egypt's Old Kingdom.The weakened waters would have been disaster for the Egyptians."Changes that affect food supply don't have to be very large to have a ripple（波浪）effect in societies."says Bill Ryan of the Lamont Doherty Earth Observatory in New York.Similar events today could be even more devastating,says team member Daniel Stanley,a scientist from the Smithsonian Institution in Washington D.C,"Anything humans do to shift the climate belts would have an even worse effect along the Nile system today because the populations have increased dramatically."Why does the author mention"Egypt's mighty pyramid builders"?A:Because they once worked miracles.B:Because they were well-built.C:Because they were actually very weak.D:Because even they were unable to rescue their civilization.
Why were the French troops in Canada defeated by the British during theSeven Years.War?（）A、Because they were not used to the weather in Canada.B、Because they did not get support from the local people.C、Because they did not receive the supplies they needed so badly.D、Because the British had larger and better settlements in Canada.
单选题Hundreds of years ago, life was much harder than it is today because _____.Athere were not modern machinesBthere was no modern medicineCboth A and BDthere were not many people
单选题It can be inferred from the passage that ______.Amost movie theaters had a pianist, a hand or an orchestraBsound-effects machines were common because they were more effectiveCfull-scale orchestras could effectively synchronize sound with picturesDgramophones came into being about the same time as moving pictures did
单选题A stayed far away from cat's unneB moved around the area freely and tearlesslyC because more sensitive to cat's smellD were more afraid of cats