共用题干第一篇Water Resources on the EarthThe second most important constituent（构成成分）of the biosphere（生物圈）is liquid water. This can only exist in a very narrow range of temperatures,since water freezes at 0℃and boils a 100℃．Life as we know it would only be possible on the surface of a planet which had temperature: somewhere within this narrow range.The earth's supply of water probably remains fairly constant in quantity.The total quantity of water is not known very accurately,but it is about enough to cover the surface of the globe to a depth of about two and three-quarter kilometers.Most of it is in the form of the salt water of the oceans一about 97 percent. The rest is fresh.But three-quarters of this is in the form of ice at the poles and or mountains and cannot be used by living systems until melted.Of the remaining fraction,which h somewhat less than one percent of the whole.There is 10—20 times as much stored underground water as there is actually on the surface.There is also a tiny,but extremely important fraction of the water supply which is present as water vapour in the atmosphere.Water vapour in the atmosphere is the channel through which the whole water circulation（循环） of the biosphere has to pass.Water evaporated（蒸发）from the surface of the oceans,from lakes and rivers and from moist（潮湿的）earth is added to it. From it the water comes out again as rain or snow,falling on either the sea or the land. There is,as might be expected, a more intensive evaporation per unit area over the sea and oceans than over the land,but there is more rainfall over the land than over the oceans and the balance is restored by the run off from the land in the form of rivers.Liquid water only exists________.A: in the center of the earthB:on the surface of our planetC:in the coastal areas of the earthD:in a very narrow range of temperatures
共用题干
第一篇
Water Resources on the Earth
The second most important constituent（构成成分）of the biosphere（生物圈）is liquid water. This can only exist in a very narrow range of temperatures,since water freezes at 0℃and boils a 100℃．Life as we know it would only be possible on the surface of a planet which had temperature: somewhere within this narrow range.
The earth's supply of water probably remains fairly constant in quantity.The total quantity of water is not known very accurately,but it is about enough to cover the surface of the globe to a depth of about two and three-quarter kilometers.Most of it is in the form of the salt water of the oceans一about 97 percent. The rest is fresh.But three-quarters of this is in the form of ice at the poles and or mountains and cannot be used by living systems until melted.Of the remaining fraction,which h somewhat less than one percent of the whole.There is 10—20 times as much stored underground water as there is actually on the surface.There is also a tiny,but extremely important fraction of the water supply which is present as water vapour in the atmosphere.
Water vapour in the atmosphere is the channel through which the whole water circulation（循环） of the biosphere has to pass.Water evaporated（蒸发）from the surface of the oceans,from lakes and rivers and from moist（潮湿的）earth is added to it. From it the water comes out again as rain or snow,falling on either the sea or the land. There is,as might be expected, a more intensive evaporation per unit area over the sea and oceans than over the land,but there is more rainfall over the land than over the oceans and the balance is restored by the run off from the land in the form of rivers.
第一篇
Water Resources on the Earth
The second most important constituent（构成成分）of the biosphere（生物圈）is liquid water. This can only exist in a very narrow range of temperatures,since water freezes at 0℃and boils a 100℃．Life as we know it would only be possible on the surface of a planet which had temperature: somewhere within this narrow range.
The earth's supply of water probably remains fairly constant in quantity.The total quantity of water is not known very accurately,but it is about enough to cover the surface of the globe to a depth of about two and three-quarter kilometers.Most of it is in the form of the salt water of the oceans一about 97 percent. The rest is fresh.But three-quarters of this is in the form of ice at the poles and or mountains and cannot be used by living systems until melted.Of the remaining fraction,which h somewhat less than one percent of the whole.There is 10—20 times as much stored underground water as there is actually on the surface.There is also a tiny,but extremely important fraction of the water supply which is present as water vapour in the atmosphere.
Water vapour in the atmosphere is the channel through which the whole water circulation（循环） of the biosphere has to pass.Water evaporated（蒸发）from the surface of the oceans,from lakes and rivers and from moist（潮湿的）earth is added to it. From it the water comes out again as rain or snow,falling on either the sea or the land. There is,as might be expected, a more intensive evaporation per unit area over the sea and oceans than over the land,but there is more rainfall over the land than over the oceans and the balance is restored by the run off from the land in the form of rivers.
Liquid water only exists________.
A: in the center of the earth
B:on the surface of our planet
C:in the coastal areas of the earth
D:in a very narrow range of temperatures
A: in the center of the earth
B:on the surface of our planet
C:in the coastal areas of the earth
D:in a very narrow range of temperatures
参考解析
解析：文章第一段的第二句讲到液态水“only exist in a very narrow range of temperatures"，虽然B（我们星球的表面）也有点道理，但是液态水对温度的要求很高，并非地球的所有表面都有液态水存在，所以答案D正确。
第二段第一句提到地球上水的供给“remains fairly constant in quantity"，数量上是恒定的，它就没有增加也不会减少，只不过会以不同的形态出现，所以选择B（保持不变）。
问题是“地球上绝大部分淡水以什么形式出现？”第二段中间提到淡水时，说到“three-quarters of this is in the form of ice at the poles and on mountains"，即3/4的淡水以冰的形式存在于两极和高山中，后面提到剩余部分的淡水存在于地下，但占比少于1%,所以选项A正确。
词义辫析题， fraction有“小部分”的意思，考虑到前面提到地球97％的水以海洋咸水的形式存在，剩下的3％则以冰的形式存在于两极和高山，余下的自然不多，所以选B。
第三段的最后一句说到“there is more rainfall over the land than over the oceans”，陆地的降雨比海洋要多，但没有提到河流和山脉的降雨比较，所以C正确。大气中的水蒸气是整个生物圈的水循环必经的途径。水从海洋的表面、湖泊、河流和潮湿的泥土中蒸发出来并补充到大气中。水以雨或雪的形式再次出现，降落在海洋或陆地上。可以预料到的是，海洋上空每单位面积的水蒸气比在陆地上空更为密集，但是，陆地比海洋有更多的降雨，水在陆地上以河流的形式流出以保持水资源的平衡。
第二段第一句提到地球上水的供给“remains fairly constant in quantity"，数量上是恒定的，它就没有增加也不会减少，只不过会以不同的形态出现，所以选择B（保持不变）。
问题是“地球上绝大部分淡水以什么形式出现？”第二段中间提到淡水时，说到“three-quarters of this is in the form of ice at the poles and on mountains"，即3/4的淡水以冰的形式存在于两极和高山中，后面提到剩余部分的淡水存在于地下，但占比少于1%,所以选项A正确。
词义辫析题， fraction有“小部分”的意思，考虑到前面提到地球97％的水以海洋咸水的形式存在，剩下的3％则以冰的形式存在于两极和高山，余下的自然不多，所以选B。
第三段的最后一句说到“there is more rainfall over the land than over the oceans”，陆地的降雨比海洋要多，但没有提到河流和山脉的降雨比较，所以C正确。大气中的水蒸气是整个生物圈的水循环必经的途径。水从海洋的表面、湖泊、河流和潮湿的泥土中蒸发出来并补充到大气中。水以雨或雪的形式再次出现，降落在海洋或陆地上。可以预料到的是，海洋上空每单位面积的水蒸气比在陆地上空更为密集，但是，陆地比海洋有更多的降雨，水在陆地上以河流的形式流出以保持水资源的平衡。
相关考题：
Water is the __46___ of all the things we eat and drink . Not many people understand this but __47____ quite true . The human body can go without ___48___ for a long time . We’ve got many examples for this . Yet two __49___ three days without water can usually make people __50____ . Man can’t live __51____ water .Many people don’t understand how ___52__ water the human body needs __53___ work well , and many people , especially young people , do not drink enough , ___54__ in very hot weather . Our body has mostly water , about 65% to 75% . That is to say about two thirds of our body is water . When we do sports , some of the water will get away from our body . __55 _ we don’t drink some water , we won’t have enough water． And if we don’t have enough water , we’ll feel tired and many of us will get ill . So you know how important water is to us .46.___________( )46. A. importantB. most importantC. more importantD. different
BThe world is not only hungry，it is also thirsty for water． this may seem strange to you，since nearly 75% of the earth is covered with water． But about 97% of this water is sea water．Man can only drink and use the other 3% fresh water that comes from rivers，lakes，under-ground and other places． And we cannot even use all of that，because some of this fresh water has been made dirty．At the moment，this small amount(数量) of fresh water is still enough for us． However，our need for water is getting greater and greater． Only if we take steps to solve this problem now，we can get away from a serious world water shortage later on． The people of the world cannot have an enjoyable life without enough clean water．On one hand we should stop wasting this little water of ours，on the other hand we should find ways to reuse it，but this has not been done widely．Today，in most large cities，water is used only once and it then returns to the sea or runs into underground places．lf we can make it clean again，it can be used once more just as if it were fresh from a spring．But even if large cities reuse its water，we still would not have enough in the future． Where．could we turn to next for water? To the ocean! How can we do to make use of this great a-mount of sea water? We can take the salt from the water to make it fresh．So if we take all these steps，we'll be in no danger of drying up!( )26． Why does the writer say that the world is thirsty for water?A． The amount of fresh water is really very small．B． The people of the world waste too much water．C． The people of the world have to drink a lot of water every day．D． There are too many people in the world needing water．
共用题干第三篇“Life Form Found" on Saturn ' s TitanScientists say they have discovered hints of alien life on the Saturn'5 moon.The discovery of a sort of life was announced after researchers at the US space agency,NASA,analyzed data from spacecraft Cassini, which pointed to the existence of methane-based form of life on Saturn's biggest moon.Scientists have reportedly discovered clues showing primitive alien beings are"breathing"in Titan's dense atmosphere filled with hydrogen.They argue that hydrogen gets absorbed before hitting Titan's planet-like surface covered with methane lakes and rivers.This,they say,points to the existence of some"bugs"consuming the hydrogen at the surface of the moon less than half the size of the Earth."We suggested hydrogen consumption because it's the obvious gas for life to consume on Titan,similar to the way we consume oxygen on Earth,"says NASA scientist Chris McKay."If these signs do turn out to be a sign of life,it would be doubly exciting because it would represent a second form of life independent from water-based life on Earth."To date,scientists have not yet detected this form of life anywhere,though there are liquid-water-based microorganisms on Earth that grow well on methane or produce it as a waste product. On Titan,wheretemperatures are around minus 17 Kelvin(minus 290 degrees Farenheit),a methane-based organism would have to use a substance that is liquid as its medium for living processes,but not water itself. Water is frozen solid on Titan'5 surface and much too cold to support life as we know it.Scientists had expected the Sun'5 interactions with chemicals in the atmosphere to produce a coating of acetylene on Titan'5 surface.But Cassini detected no acetylene on the surface.The absence of detectable acetylene on the Titan's surface can very well have a non-biological explana-tion,said Mark Allen,a principal investigator of the NASA Titan team."Scientific conservatism suggests that a biological explanation should be the last choice after all non- biological explanations are addressed,"Allen said."We have a lot of work to do to rule out possible non-bio- logical explanations.It is more likely that a chemical process,without biology,can explain these results."What do scientists claim to have found about Saturn?A: Water-based life on it.B: Methane-based life on its biggest moon.C:A new moon moving around it.D:Earthlike life on its biggest moon.
共用题干第三篇“Life Form Found" on Saturn ' s TitanScientists say they have discovered hints of alien life on the Saturn'5 moon.The discovery of a sort of life was announced after researchers at the US space agency,NASA,analyzed data from spacecraft Cassini, which pointed to the existence of methane-based form of life on Saturn's biggest moon.Scientists have reportedly discovered clues showing primitive alien beings are"breathing"in Titan's dense atmosphere filled with hydrogen.They argue that hydrogen gets absorbed before hitting Titan's planet-like surface covered with methane lakes and rivers.This,they say,points to the existence of some"bugs"consuming the hydrogen at the surface of the moon less than half the size of the Earth."We suggested hydrogen consumption because it's the obvious gas for life to consume on Titan,similar to the way we consume oxygen on Earth,"says NASA scientist Chris McKay."If these signs do turn out to be a sign of life,it would be doubly exciting because it would represent a second form of life independent from water-based life on Earth."To date,scientists have not yet detected this form of life anywhere,though there are liquid-water-based microorganisms on Earth that grow well on methane or produce it as a waste product. On Titan,wheretemperatures are around minus 17 Kelvin(minus 290 degrees Farenheit),a methane-based organism would have to use a substance that is liquid as its medium for living processes,but not water itself. Water is frozen solid on Titan'5 surface and much too cold to support life as we know it.Scientists had expected the Sun'5 interactions with chemicals in the atmosphere to produce a coating of acetylene on Titan'5 surface.But Cassini detected no acetylene on the surface.The absence of detectable acetylene on the Titan's surface can very well have a non-biological explana-tion,said Mark Allen,a principal investigator of the NASA Titan team."Scientific conservatism suggests that a biological explanation should be the last choice after all non- biological explanations are addressed,"Allen said."We have a lot of work to do to rule out possible non-bio- logical explanations.It is more likely that a chemical process,without biology,can explain these results."Which of the following can replace the title of this passage?A:Different Life Form,a Possibility.B:Earthlike Living Beings Found on Titan.C:Finding of One More Moon of Saturn.D:Titan,a New Satellite Discovered.
共用题干第三篇“Life Form Found" on Saturn ' s TitanScientists say they have discovered hints of alien life on the Saturn'5 moon.The discovery of a sort of life was announced after researchers at the US space agency,NASA,analyzed data from spacecraft Cassini, which pointed to the existence of methane-based form of life on Saturn's biggest moon.Scientists have reportedly discovered clues showing primitive alien beings are"breathing"in Titan's dense atmosphere filled with hydrogen.They argue that hydrogen gets absorbed before hitting Titan's planet-like surface covered with methane lakes and rivers.This,they say,points to the existence of some"bugs"consuming the hydrogen at the surface of the moon less than half the size of the Earth."We suggested hydrogen consumption because it's the obvious gas for life to consume on Titan,similar to the way we consume oxygen on Earth,"says NASA scientist Chris McKay."If these signs do turn out to be a sign of life,it would be doubly exciting because it would represent a second form of life independent from water-based life on Earth."To date,scientists have not yet detected this form of life anywhere,though there are liquid-water-based microorganisms on Earth that grow well on methane or produce it as a waste product. On Titan,wheretemperatures are around minus 17 Kelvin(minus 290 degrees Farenheit),a methane-based organism would have to use a substance that is liquid as its medium for living processes,but not water itself. Water is frozen solid on Titan'5 surface and much too cold to support life as we know it.Scientists had expected the Sun'5 interactions with chemicals in the atmosphere to produce a coating of acetylene on Titan'5 surface.But Cassini detected no acetylene on the surface.The absence of detectable acetylene on the Titan's surface can very well have a non-biological explana-tion,said Mark Allen,a principal investigator of the NASA Titan team."Scientific conservatism suggests that a biological explanation should be the last choice after all non- biological explanations are addressed,"Allen said."We have a lot of work to do to rule out possible non-bio- logical explanations.It is more likely that a chemical process,without biology,can explain these results."The expression"this form of life"in Paragraph 5 refer to_____________.A: water-based lifeB: oxygen-based lifeC: methane-based lifeD: liquid-based microorganisms
共用题干第三篇“Life Form Found" on Saturn ' s TitanScientists say they have discovered hints of alien life on the Saturn'5 moon.The discovery of a sort of life was announced after researchers at the US space agency,NASA,analyzed data from spacecraft Cassini, which pointed to the existence of methane-based form of life on Saturn's biggest moon.Scientists have reportedly discovered clues showing primitive alien beings are"breathing"in Titan's dense atmosphere filled with hydrogen.They argue that hydrogen gets absorbed before hitting Titan's planet-like surface covered with methane lakes and rivers.This,they say,points to the existence of some"bugs"consuming the hydrogen at the surface of the moon less than half the size of the Earth."We suggested hydrogen consumption because it's the obvious gas for life to consume on Titan,similar to the way we consume oxygen on Earth,"says NASA scientist Chris McKay."If these signs do turn out to be a sign of life,it would be doubly exciting because it would represent a second form of life independent from water-based life on Earth."To date,scientists have not yet detected this form of life anywhere,though there are liquid-water-based microorganisms on Earth that grow well on methane or produce it as a waste product. On Titan,wheretemperatures are around minus 17 Kelvin(minus 290 degrees Farenheit),a methane-based organism would have to use a substance that is liquid as its medium for living processes,but not water itself. Water is frozen solid on Titan'5 surface and much too cold to support life as we know it.Scientists had expected the Sun'5 interactions with chemicals in the atmosphere to produce a coating of acetylene on Titan'5 surface.But Cassini detected no acetylene on the surface.The absence of detectable acetylene on the Titan's surface can very well have a non-biological explana-tion,said Mark Allen,a principal investigator of the NASA Titan team."Scientific conservatism suggests that a biological explanation should be the last choice after all non- biological explanations are addressed,"Allen said."We have a lot of work to do to rule out possible non-bio- logical explanations.It is more likely that a chemical process,without biology,can explain these results."Which of the following statements about Titan is true?A:It is as large as the Earth.B:There is acetylene on its surface.C:Water on it acts as a life supporting medium.D:Hydrogen consumption is reported to be on it.
共用题干第三篇“Life Form Found" on Saturn ' s TitanScientists say they have discovered hints of alien life on the Saturn'5 moon.The discovery of a sort of life was announced after researchers at the US space agency,NASA,analyzed data from spacecraft Cassini, which pointed to the existence of methane-based form of life on Saturn's biggest moon.Scientists have reportedly discovered clues showing primitive alien beings are"breathing"in Titan's dense atmosphere filled with hydrogen.They argue that hydrogen gets absorbed before hitting Titan's planet-like surface covered with methane lakes and rivers.This,they say,points to the existence of some"bugs"consuming the hydrogen at the surface of the moon less than half the size of the Earth."We suggested hydrogen consumption because it's the obvious gas for life to consume on Titan,similar to the way we consume oxygen on Earth,"says NASA scientist Chris McKay."If these signs do turn out to be a sign of life,it would be doubly exciting because it would represent a second form of life independent from water-based life on Earth."To date,scientists have not yet detected this form of life anywhere,though there are liquid-water-based microorganisms on Earth that grow well on methane or produce it as a waste product. On Titan,wheretemperatures are around minus 17 Kelvin(minus 290 degrees Farenheit),a methane-based organism would have to use a substance that is liquid as its medium for living processes,but not water itself. Water is frozen solid on Titan'5 surface and much too cold to support life as we know it.Scientists had expected the Sun'5 interactions with chemicals in the atmosphere to produce a coating of acetylene on Titan'5 surface.But Cassini detected no acetylene on the surface.The absence of detectable acetylene on the Titan's surface can very well have a non-biological explana-tion,said Mark Allen,a principal investigator of the NASA Titan team."Scientific conservatism suggests that a biological explanation should be the last choice after all non- biological explanations are addressed,"Allen said."We have a lot of work to do to rule out possible non-bio- logical explanations.It is more likely that a chemical process,without biology,can explain these results."It can be inferred from Mark Allen's address that_____________.A:scientists are trying to confirm these is life on TitanB:scientists agree that a chemical process is a convincing explanationC:scientists share the opinion that a biological explanation is reasonableD:scientists are arguing over whether there is life on Titan
共用题干第二篇Human and the EarthIn terms of the evolution of life on Earth,human beings have just arrived.Despite their shori time on Earth,however,people have brought about enormous changes to the surface of the planet一changes far out of proportion to the interval of time they have occupied it.People have more control over their surroundings than any other species on Earth.With the combination of intelligence and manual skill(allowing us to make and use tools),people have found ways to use plant and animal resources,mineral ores,fuels,and many other materials and resources from the Earth.As the number of people on Earth increases,it becomes increasingly difficult for the population to survive on the resources of the land.The amount of land is limited.Although agricultural production can be increased by use of machinery such as tractors and the addition of fertilizer,the land ultimately can produce only so much food and no more.As the human population grows,people consume more.Clearly,some locations on Earth already have too many people;in many of these areas,future increases will surely bring about more poverty and suffering. Yet people in rich nations use proportionally far more of the available resources than people in poorer nations.As they consume these resources without restraint,they also waste large amounts of them.People are only a very small fraction of all the living things on the planet.Yet their numbers create a drain on resources that can't be renewed.For example,the amount of water on Earth is limited,this water is cleaned through natural processes.However,the natural processes for filtering water can clean only a certain amount of water by removing the pollution.Likewise,a limited amount of petroleum can be found under the Earth's surface.Petroleum is a valuable resource.Should people use it up to manufacture petrol for automobiles?As people work to control the planet and make life comfortable,are they using up resources that are needed for their survival?in terms of the evolution of life on Earth,the history of human beings is_______.A:very short B:very longC:as long as that of other animals D:as long as that of the Earth
共用题干第二篇Human and the EarthIn terms of the evolution of life on Earth,human beings have just arrived.Despite their shori time on Earth,however,people have brought about enormous changes to the surface of the planet一changes far out of proportion to the interval of time they have occupied it.People have more control over their surroundings than any other species on Earth.With the combination of intelligence and manual skill(allowing us to make and use tools),people have found ways to use plant and animal resources,mineral ores,fuels,and many other materials and resources from the Earth.As the number of people on Earth increases,it becomes increasingly difficult for the population to survive on the resources of the land.The amount of land is limited.Although agricultural production can be increased by use of machinery such as tractors and the addition of fertilizer,the land ultimately can produce only so much food and no more.As the human population grows,people consume more.Clearly,some locations on Earth already have too many people;in many of these areas,future increases will surely bring about more poverty and suffering. Yet people in rich nations use proportionally far more of the available resources than people in poorer nations.As they consume these resources without restraint,they also waste large amounts of them.People are only a very small fraction of all the living things on the planet.Yet their numbers create a drain on resources that can't be renewed.For example,the amount of water on Earth is limited,this water is cleaned through natural processes.However,the natural processes for filtering water can clean only a certain amount of water by removing the pollution.Likewise,a limited amount of petroleum can be found under the Earth's surface.Petroleum is a valuable resource.Should people use it up to manufacture petrol for automobiles?As people work to control the planet and make life comfortable,are they using up resources that are needed for their survival?Which of the following statements about resources on Earth is not correct?A:They can not be renewed.B:Water is a kind of resource which can not be renewed.C:Some of the resources are valuable.D:Many resources can be recycled so we don't need to worry about them.
共用题干Europa's Watery UnderworldEuropa,one of Jupiter's 63 known moons,looks bright and icy on the surface.But appearances can be deceiving:Miles within its cracked,frigid shell,Europa probably hides giant pools of liquid water. Where scientists find liquid water,they hope to find life as well.Since we can't go diving into Europa's depths just yet,scientists instead have to investigate the moon's surface for clues to what lies beneath.In a new study,scientists investigated one group of strange ice patterns on Europa and concluded that the formations mark the top of an underground pool that holds as much water as the U.S.Great Lakes.Pictures of Europa,which is slightly smaller than Earth's moon,clearly show a tangled,icy mishmash of lines and cracks known as"chaos terrains".These chaotic places cover more than half of Europa. For more than 10 years,scientists have wondered what causes the formations.The new study suggests that they arise from the mixing of vast underground stores of liquid water with icy material near the surface.For scientists who suspect that Europa also may be hiding life beneath its icy surface,the news about the new lake is exciting."It would be great if these lakes harbored life,"Britney Schmidt,a planetary scientist who worked onthe study,told Science News."But even if they didn't,they say that Europa is doing something interesting and active right now."Schmidt,a scientist at the University of Texas at Austin,and her colleagues wanted to know how chaos terrains form.Since they couldn't rocket to Europa to see for themselves,they searched for similar forma- tions here on Earth.They studied collapsed ice shelves in Antarctica and icy caps on volcanoes in Iceland. Those features on Earth formed when liquid water mixed with ice.The scientists now suspect something similar might be happening on Europa:that as water and ice of different temperatures mingle and shift,the surface fractures.This would explain the jumbled ice sculptures."Fracturing catastrophically disrupts the ice in the same way that it causes ice shelves to collapse on Earth,"Schmidt told Science News.She and her team found that the process could be causing chaos terrains to form quickly on Europa.The new study suggests that on this moon,elements such as oxygen from the surface blend with the deep bodies of water. That mixture may create an environment that supports life.Schmidt and her colleagues are the first group of scientists reaching Europa.A:RightB:WrongC:Not mentioned
共用题干Europa's Watery UnderworldEuropa,one of Jupiter's 63 known moons,looks bright and icy on the surface.But appearances can be deceiving:Miles within its cracked,frigid shell,Europa probably hides giant pools of liquid water. Where scientists find liquid water,they hope to find life as well.Since we can't go diving into Europa's depths just yet,scientists instead have to investigate the moon's surface for clues to what lies beneath.In a new study,scientists investigated one group of strange ice patterns on Europa and concluded that the formations mark the top of an underground pool that holds as much water as the U.S.Great Lakes.Pictures of Europa,which is slightly smaller than Earth's moon,clearly show a tangled,icy mishmash of lines and cracks known as"chaos terrains".These chaotic places cover more than half of Europa. For more than 10 years,scientists have wondered what causes the formations.The new study suggests that they arise from the mixing of vast underground stores of liquid water with icy material near the surface.For scientists who suspect that Europa also may be hiding life beneath its icy surface,the news about the new lake is exciting."It would be great if these lakes harbored life,"Britney Schmidt,a planetary scientist who worked onthe study,told Science News."But even if they didn't,they say that Europa is doing something interesting and active right now."Schmidt,a scientist at the University of Texas at Austin,and her colleagues wanted to know how chaos terrains form.Since they couldn't rocket to Europa to see for themselves,they searched for similar forma- tions here on Earth.They studied collapsed ice shelves in Antarctica and icy caps on volcanoes in Iceland. Those features on Earth formed when liquid water mixed with ice.The scientists now suspect something similar might be happening on Europa:that as water and ice of different temperatures mingle and shift,the surface fractures.This would explain the jumbled ice sculptures."Fracturing catastrophically disrupts the ice in the same way that it causes ice shelves to collapse on Earth,"Schmidt told Science News.She and her team found that the process could be causing chaos terrains to form quickly on Europa.The new study suggests that on this moon,elements such as oxygen from the surface blend with the deep bodies of water. That mixture may create an environment that supports life.The liquid water of an underground pool of Europa is estimated as much as the volume of the U.S.Great Lakes.A:RightB:WrongC:Not mentioned
共用题干Europa's Watery UnderworldEuropa,one of Jupiter's 63 known moons,looks bright and icy on the surface.But appearances can be deceiving:Miles within its cracked,frigid shell,Europa probably hides giant pools of liquid water. Where scientists find liquid water,they hope to find life as well.Since we can't go diving into Europa's depths just yet,scientists instead have to investigate the moon's surface for clues to what lies beneath.In a new study,scientists investigated one group of strange ice patterns on Europa and concluded that the formations mark the top of an underground pool that holds as much water as the U.S.Great Lakes.Pictures of Europa,which is slightly smaller than Earth's moon,clearly show a tangled,icy mishmash of lines and cracks known as"chaos terrains".These chaotic places cover more than half of Europa. For more than 10 years,scientists have wondered what causes the formations.The new study suggests that they arise from the mixing of vast underground stores of liquid water with icy material near the surface.For scientists who suspect that Europa also may be hiding life beneath its icy surface,the news about the new lake is exciting."It would be great if these lakes harbored life,"Britney Schmidt,a planetary scientist who worked onthe study,told Science News."But even if they didn't,they say that Europa is doing something interesting and active right now."Schmidt,a scientist at the University of Texas at Austin,and her colleagues wanted to know how chaos terrains form.Since they couldn't rocket to Europa to see for themselves,they searched for similar forma- tions here on Earth.They studied collapsed ice shelves in Antarctica and icy caps on volcanoes in Iceland. Those features on Earth formed when liquid water mixed with ice.The scientists now suspect something similar might be happening on Europa:that as water and ice of different temperatures mingle and shift,the surface fractures.This would explain the jumbled ice sculptures."Fracturing catastrophically disrupts the ice in the same way that it causes ice shelves to collapse on Earth,"Schmidt told Science News.She and her team found that the process could be causing chaos terrains to form quickly on Europa.The new study suggests that on this moon,elements such as oxygen from the surface blend with the deep bodies of water. That mixture may create an environment that supports life.Europa is the most recently discovered one among Jupiter's moons.A:RightB:WrongC:Not mentioned
共用题干Europa's Watery UnderworldEuropa,one of Jupiter's 63 known moons,looks bright and icy on the surface.But appearances can be deceiving:Miles within its cracked,frigid shell,Europa probably hides giant pools of liquid water. Where scientists find liquid water,they hope to find life as well.Since we can't go diving into Europa's depths just yet,scientists instead have to investigate the moon's surface for clues to what lies beneath.In a new study,scientists investigated one group of strange ice patterns on Europa and concluded that the formations mark the top of an underground pool that holds as much water as the U.S.Great Lakes.Pictures of Europa,which is slightly smaller than Earth's moon,clearly show a tangled,icy mishmash of lines and cracks known as"chaos terrains".These chaotic places cover more than half of Europa. For more than 10 years,scientists have wondered what causes the formations.The new study suggests that they arise from the mixing of vast underground stores of liquid water with icy material near the surface.For scientists who suspect that Europa also may be hiding life beneath its icy surface,the news about the new lake is exciting."It would be great if these lakes harbored life,"Britney Schmidt,a planetary scientist who worked onthe study,told Science News."But even if they didn't,they say that Europa is doing something interesting and active right now."Schmidt,a scientist at the University of Texas at Austin,and her colleagues wanted to know how chaos terrains form.Since they couldn't rocket to Europa to see for themselves,they searched for similar forma- tions here on Earth.They studied collapsed ice shelves in Antarctica and icy caps on volcanoes in Iceland. Those features on Earth formed when liquid water mixed with ice.The scientists now suspect something similar might be happening on Europa:that as water and ice of different temperatures mingle and shift,the surface fractures.This would explain the jumbled ice sculptures."Fracturing catastrophically disrupts the ice in the same way that it causes ice shelves to collapse on Earth,"Schmidt told Science News.She and her team found that the process could be causing chaos terrains to form quickly on Europa.The new study suggests that on this moon,elements such as oxygen from the surface blend with the deep bodies of water. That mixture may create an environment that supports life.The strange ice patterns on Europa are formed as a result of a mixture of liquid water and solid material underground water pool.A:RightB:WrongC:Not mentioned
共用题干Europa's Watery UnderworldEuropa,one of Jupiter's 63 known moons,looks bright and icy on the surface.But appearances can be deceiving:Miles within its cracked,frigid shell,Europa probably hides giant pools of liquid water. Where scientists find liquid water,they hope to find life as well.Since we can't go diving into Europa's depths just yet,scientists instead have to investigate the moon's surface for clues to what lies beneath.In a new study,scientists investigated one group of strange ice patterns on Europa and concluded that the formations mark the top of an underground pool that holds as much water as the U.S.Great Lakes.Pictures of Europa,which is slightly smaller than Earth's moon,clearly show a tangled,icy mishmash of lines and cracks known as"chaos terrains".These chaotic places cover more than half of Europa. For more than 10 years,scientists have wondered what causes the formations.The new study suggests that they arise from the mixing of vast underground stores of liquid water with icy material near the surface.For scientists who suspect that Europa also may be hiding life beneath its icy surface,the news about the new lake is exciting."It would be great if these lakes harbored life,"Britney Schmidt,a planetary scientist who worked onthe study,told Science News."But even if they didn't,they say that Europa is doing something interesting and active right now."Schmidt,a scientist at the University of Texas at Austin,and her colleagues wanted to know how chaos terrains form.Since they couldn't rocket to Europa to see for themselves,they searched for similar forma- tions here on Earth.They studied collapsed ice shelves in Antarctica and icy caps on volcanoes in Iceland. Those features on Earth formed when liquid water mixed with ice.The scientists now suspect something similar might be happening on Europa:that as water and ice of different temperatures mingle and shift,the surface fractures.This would explain the jumbled ice sculptures."Fracturing catastrophically disrupts the ice in the same way that it causes ice shelves to collapse on Earth,"Schmidt told Science News.She and her team found that the process could be causing chaos terrains to form quickly on Europa.The new study suggests that on this moon,elements such as oxygen from the surface blend with the deep bodies of water. That mixture may create an environment that supports life.The existence of liquid water is a necessity for a life-support environment.A:RightB:WrongC:Not mentioned
共用题干第一篇Water Resources on the EarthThe second most important constituent（构成成分）of the biosphere（生物圈）is liquid water. This can only exist in a very narrow range of temperatures,since water freezes at 0℃and boils a 100℃．Life as we know it would only be possible on the surface of a planet which had temperature: somewhere within this narrow range.The earth's supply of water probably remains fairly constant in quantity.The total quantity of water is not known very accurately,but it is about enough to cover the surface of the globe to a depth of about two and three-quarter kilometers.Most of it is in the form of the salt water of the oceans一about 97 percent. The rest is fresh.But three-quarters of this is in the form of ice at the poles and or mountains and cannot be used by living systems until melted.Of the remaining fraction,which h somewhat less than one percent of the whole.There is 10—20 times as much stored underground water as there is actually on the surface.There is also a tiny,but extremely important fraction of the water supply which is present as water vapour in the atmosphere.Water vapour in the atmosphere is the channel through which the whole water circulation（循环） of the biosphere has to pass.Water evaporated（蒸发）from the surface of the oceans,from lakes and rivers and from moist（潮湿的）earth is added to it. From it the water comes out again as rain or snow,falling on either the sea or the land. There is,as might be expected, a more intensive evaporation per unit area over the sea and oceans than over the land,but there is more rainfall over the land than over the oceans and the balance is restored by the run off from the land in the form of rivers.The word"fraction"in the second paragraph means________.A:a large areaB:a very small amountC:an important systemD:a major source of information
共用题干第一篇Water Resources on the EarthThe second most important constituent（构成成分）of the biosphere（生物圈）is liquid water. This can only exist in a very narrow range of temperatures,since water freezes at 0℃and boils a 100℃．Life as we know it would only be possible on the surface of a planet which had temperature: somewhere within this narrow range.The earth's supply of water probably remains fairly constant in quantity.The total quantity of water is not known very accurately,but it is about enough to cover the surface of the globe to a depth of about two and three-quarter kilometers.Most of it is in the form of the salt water of the oceans一about 97 percent. The rest is fresh.But three-quarters of this is in the form of ice at the poles and or mountains and cannot be used by living systems until melted.Of the remaining fraction,which h somewhat less than one percent of the whole.There is 10—20 times as much stored underground water as there is actually on the surface.There is also a tiny,but extremely important fraction of the water supply which is present as water vapour in the atmosphere.Water vapour in the atmosphere is the channel through which the whole water circulation（循环） of the biosphere has to pass.Water evaporated（蒸发）from the surface of the oceans,from lakes and rivers and from moist（潮湿的）earth is added to it. From it the water comes out again as rain or snow,falling on either the sea or the land. There is,as might be expected, a more intensive evaporation per unit area over the sea and oceans than over the land,but there is more rainfall over the land than over the oceans and the balance is restored by the run off from the land in the form of rivers.Most of the fresh water on Earth________.A:is in the form of ice at the poles and on mountainsB:is stored undergroundC:is found in rivers and lakesD:comes from the rain
共用题干第一篇Water Resources on the EarthThe second most important constituent（构成成分）of the biosphere（生物圈）is liquid water. This can only exist in a very narrow range of temperatures,since water freezes at 0℃and boils a 100℃．Life as we know it would only be possible on the surface of a planet which had temperature: somewhere within this narrow range.The earth's supply of water probably remains fairly constant in quantity.The total quantity of water is not known very accurately,but it is about enough to cover the surface of the globe to a depth of about two and three-quarter kilometers.Most of it is in the form of the salt water of the oceans一about 97 percent. The rest is fresh.But three-quarters of this is in the form of ice at the poles and or mountains and cannot be used by living systems until melted.Of the remaining fraction,which h somewhat less than one percent of the whole.There is 10—20 times as much stored underground water as there is actually on the surface.There is also a tiny,but extremely important fraction of the water supply which is present as water vapour in the atmosphere.Water vapour in the atmosphere is the channel through which the whole water circulation（循环） of the biosphere has to pass.Water evaporated（蒸发）from the surface of the oceans,from lakes and rivers and from moist（潮湿的）earth is added to it. From it the water comes out again as rain or snow,falling on either the sea or the land. There is,as might be expected, a more intensive evaporation per unit area over the sea and oceans than over the land,but there is more rainfall over the land than over the oceans and the balance is restored by the run off from the land in the form of rivers.There is more of rainfall________.A:over the mountains than over the riversB:over the rivers than over the mountainsC:over the land than over the oceansD:over the oceans than over the land
共用题干第一篇Water Resources on the EarthThe second most important constituent（构成成分）of the biosphere（生物圈）is liquid water. This can only exist in a very narrow range of temperatures,since water freezes at 0℃and boils a 100℃．Life as we know it would only be possible on the surface of a planet which had temperature: somewhere within this narrow range.The earth's supply of water probably remains fairly constant in quantity.The total quantity of water is not known very accurately,but it is about enough to cover the surface of the globe to a depth of about two and three-quarter kilometers.Most of it is in the form of the salt water of the oceans一about 97 percent. The rest is fresh.But three-quarters of this is in the form of ice at the poles and or mountains and cannot be used by living systems until melted.Of the remaining fraction,which h somewhat less than one percent of the whole.There is 10—20 times as much stored underground water as there is actually on the surface.There is also a tiny,but extremely important fraction of the water supply which is present as water vapour in the atmosphere.Water vapour in the atmosphere is the channel through which the whole water circulation（循环） of the biosphere has to pass.Water evaporated（蒸发）from the surface of the oceans,from lakes and rivers and from moist（潮湿的）earth is added to it. From it the water comes out again as rain or snow,falling on either the sea or the land. There is,as might be expected, a more intensive evaporation per unit area over the sea and oceans than over the land,but there is more rainfall over the land than over the oceans and the balance is restored by the run off from the land in the form of rivers.The total quantity of water on Earth________.A:has greatly increased in recent yearsB:remains almost unchangedC:is decreasing constantlyD:is affected by global warming
共用题干Where Did the Earth's Water Come From?Earth is located within the"snow line"of the solar system,the region closest to the Sun where H2 0 is primarily in liquid or gaseous form,if at all.______(46)The snow line phenomena is reflected in the water content of planets like Mercury,Venus,and Mars. Water is absent on Mercury.On Venus,H2O only exists as a trace element in the atmosphere.Mars only has a thin veneer of ice in its polar regions.In general,water is rare within the snow line.Why does Earth have so much water relative to the other inner planets?71%of the surface is covered in the oceans,more than half of which is deeper than 3,000 meters,with an approximate total volume of 1.3 billion cu km.______(47)There are various theories as to where all the Earth's water came from,but several theories have fared better than the others.______(48)When the Earth was in the process of forming,with a radius just 40%smaller than at present,it would have had enough gravity to hold on to a tenuous atmosphere with water vapor. The first water vapor on the planet would have come from the planet's internals,where volatile(low weight)chemicals would have a tendency to float to the top,and heavy chemicals(iron and nickel)would sink.Though the first of Earth's water came about through volcanism,this alone probably didn't produce enough to form stable pools on the surface.______(49)Comparing the isotope ratios of water on Earth and water from comets and asteroids has revealed that the majority of the Earth's water comes from asteroids.Throughout its history,Earth's water has increased in volume due to biological processes. In the early seas of Earth,hydrogen sulfide would have been in great supply,which,when reacted with carbon dioxide from the atmosphere during photosynthesis in sulfide-reducing bacteria,would have produced hydrogen,sulfur,and water.______(50)________（49）A: More water was added to the planet during several hypothesized large impacts from asteroids from the outer asteroid belt.B:We know that the oceans existed as early as 100 million years after the formation of the Earth.C:Still,the oceans only make up 0.023%of the Earth's total mass.D:Astronomers say Earth s water may have come from space.E:The snow line is located in the outerasteroid belt,between the orbits of Mars and Jupiter. F: Many geologists believe that the majority of Earth's water generated through this process.
共用题干The SeaWhat do you know about the sea?We know that it looks very pretty when the sun is shining on it.We also know that it can be very rough when there is a strong wind.What other things do we know about it?The first thing to remember is that the sea is very big.When you look at the map of the world you will find there is more water than land.The sea covers three quarters of the world.The sea is also very deep in some places.It is not deep everywhere.Some parts of the sea are very shal-low.But in some places the depth of the sea is very great.There is one spot,near Japan,where the sea is nearly 11 kilometers deep!The highest mountain in the world is about 9 kilometers high.If that mountainwere put into the sea at that place,there would be 2 kilometers of water above it！What a deep place!If you have swum in the sea,you know that it is salty.You can taste the salt,Rivers,which fi0w into the sea.carry salt from the land into the sea.Some parts of the sea are saltier than other parts,There i、one sea,called the Dead Sea,which is very salty.It is so salty that swimmers cannot sink!Fish cannot live in theDead Sea!In most parts of the sea,there are plenty of fishes and plants.Some live near the top of the sca.Othurslive deep down.There are millions of tiny living things that float in the sea.These floating things are so smallthat it is hard to see them.Many fish live by eating them.The sea can be very cold.Divers,who go deep down in the sea,know this.On the top the water may bewarm.When the diver goes downwards,the sea becomnes colder and colder. Another thing happens.When the diver goes deeper,the water above presses down on him.It squeezes him.Then the diver has to wear clothesmade of metal.But he cannot go very deep.Some people who wanted to go very deep used a very strong diving ship!They went down to the deepest part of the sea in it.They went down to a depth of eleven kilometers!The deeper a diver goes down in the sea,the greater water pressure he bears?A:RightB: WrongC:Not mentioned
The water we drink and use is running short in the world.We all have to learn how to stop wasting our limited water.One of the steps we should take is to find ways of reusing it.Experiments have already been done in this field.Today in most large cities,fresh water is used only once,then it runs into waste system.But it is possible to pipe the used water to a purifying factory.There it can be filtered and treated with chemicals so that it can be used again,just as it were fresh from a spring.But even if every large city purified and reused its water,we still would not have enough.Then we could turn to the oceans.All we’d have to do to make use of the seawater on earth is to get rid of the salt.This process is called desalinization,and it is already in use in many parts of the world.The way to stop wasting our limited water is to________.A.do experiments with waterB.purify the used water and reuse itC.use fresh water once againD.make use of seawater
问答题Directions: In this section, there is one passage followed by 5 questions. Read the passage carefully, then answer the questions in as few words as possible (not more than 10 words). Remember to write the answers on the Answer Sheet. Questions 1-5 are based on the following passage. If you were on a distant planet, and if you had instruments that could tell you the composition of Earth’s atmosphere, how would you know there was life on this planet?Water in the atmosphere would suggest there could be water on the surface, and as we all know water is considered crucial to life. But water would only suggest that life is possible. It wouldn’t prove it’s there. Carbon? That basic component of “life as we know it?” Not necessarily. A diamond is pure carbon, and it may be pretty, but it isn’t alive. What really sets Earth apart is nitrogen, which makes up 80 percent of the planet’s atmosphere. And it’s there only because there is abundant life on Earth, say scientists at the University of Southern California The report grew out of a class discussion two years ago in a course taught by Capone and Kenneth Nealson, professor of earth sciences. Students were asked to come up with different ideas about searching for life on other planets. What is a distinct “signature,” as Capone puts it, that would show there is life on another planet? That’s a question that has been kicked around in many quarters in recent decades, especially since all efforts to find some form of life, no matter whether on Mars or in the distant reaches of space, have failed. At least so far. The current effort to search for some evidence of life on Mars focuses primarily on the search for water, because it has long been believed that water, or at least some fluid, is necessary for the chemical processes that lead life to take place. But that’s probably the wrong approach, the USC group argues. “It’s hard to imagine life without water, but it’s easy to imagine water without life,” says Nealson, who was on the Mars team before moving to USC. But nitrogen would be a much clearer signature of life. Only about 2 percent to 3 percent of the Martian atmosphere is nitrogen. That’s just a trace, and it probably means there is no life on Mars today, and if there was in the past, it probably ended many, many years ago. But, the USC team adds quickly, that doesn’t mean there’s no life anywhere else in the universe. They don’t know where, of course, but they may have found a way to narrow down the search. Look first for nitrogen, then look for biological activity that should be there. So if life exists elsewhere, and is similar to life as we know it, there should be nitrogen, and that’s what we should be looking for first, the researchers say. If they don’t find nitrogen on Mars, Capone says, “that will probably bring us to the conclusion that there likely never was life on Mars.” But how about elsewhere? Could this technique be used to search for life in other solar systems? Maybe. It might be possible to detect a nitrogen-rich atmosphere around a planet orbiting another star, but not yet. Current instruments aren’t that sensitive. If they ever are, the search for life might be narrowed down to the most promising prospects, chiefly because of the presence of nitrogen. And won’t that be fun! Questions: 1．What can suggest life is possible but cannot be proved according to the author? 2．What is a clear “signature” of life on another planet according to Capone? 3．What is considered as a wrong way to search for evidence of life on Mars? 4．What can probably prove there is no life on Mars today based on the new theory? 5．Why is it impossible to use the new technique to search for life in other solar systems now?
问答题The second most important constituent of the biosphere is liquid water.This can only exist in a very narrow range of temperatures, since water freezesat 0℃ and boils at 100℃ This is only a tiny range compared with the low tem-peratures of some other planets and the hot interior of the earth, let the tem- 1．_______perature of the sun. As we know, life would only be possible on the face of a 2．_______planet had temperatures somewhere within this range. 3．_______ The earth’s supply of water probably remains quite fairly constant in 4．_______quantity. A certain number of hydrogen atoms, which are one of the mainconstituents of water, are lost by escaping from the atmosphere to out space, 5．_______but they are probably just about replaced by new water rising away from the 6．_______depths of the earth during volcanic action. The total quantity of water is notknown, and it is about enough to cover the surface of the globe to a depth of 7．_______about two and three-quarter kms. Most of it—97%—is in the form of the saltwaters of the oceans. The rest is fresh, but three quarter of this is in the form of 8．_______ice at the Poles and on mountains, and cannot be used by living systems when 9．_______melted. Of the remaining fraction, which is somewhat fewer than 1% of the 10．_______whole, there is 10-20 times as much stored as underground water as is actual-ly on the surface. There is also a minor, but extremely important, fraction ofthe water supply which is present as water vapour in the atmosphere.欢迎使用ueditor!
问答题Most people would describe water like a colorless liquid. They (1) _______would know that in very cold conditions it becomes a solid calledice and that when heating on a fire it becomes a vapor called steam. (2) _______However, water, they would say, is a liquid. We have learned thatwater consists of molecules composed with two atoms of hydrogen (3) _______and one atom of oxygen, which we describe by the formula H2O.This is equally true of the solid called ice and the gas called steam.Chemically there is no difference between the gas, the liquid, andthe solid, all of which is made up of molecules with the formula H2O. (4) _______This is true of other chemical substances; most of them can exist asgases or as liquids or as solids. We may normally think of iron as asolid, but if we will heat it in a furnace, it will melt and become a (5) _______liquid, and at very high temperatures it will become a gas. Nothingvery permanent occurs when a gas changes into a liquid or a solid.Everyone knows that ice, which has been made by freezing water,can be melted again by warmed and that steam can be condensed (6) _______on a cold surface to become liquid water. In fact, it is only becausewater is so a familiar substance that different names are used for (7) _______the solid, liquid and gas. Most substances are only familiar with (8) _______us in one state, because the temperatures requiring to turn them (9) _______into gases are very high, or the temperatures necessary to turn theminto solids are so low. Water is an exception in this respect, whichis another reason why its three states have given three different (10) _______names.
单选题What is an advantage of using foam in fire fighting?（）AIt is MOST effective on very hot oil fires where the temperatures of the liquid exceed 100°C (212°F)BMost foams can be used with dry chemicals to attack a fire by two methodsCFoam is effective on combustible metal firesDFoam can be made with seawater or fresh water
问答题Practice 5 Water is essential for life. Yet many millions of people around the world face water shortages. Many millions of children die every year from water-borne diseases. And drought regularly afflicts some of the world’s poorest countries. The world needs to respond much better. We need to increase water efficiency, especially in agriculture. We need to free women and girls from the daily chore of hauling water. We must involve leaders of countries in decision-making on water management. We need to make sanitation a priority. This is where progress is lagging most. And we must show that water resources need not be a source of conflict. Instead, they can be a catalyst for cooperation. Significant gains have been made. But a major effort is still required. Our goal is to meet the internationally agreed targets for water and sanitation by 2015, and to build the foundation for further progress in the years beyond. This is an urgent matter of human development, and human dignity. Together, we can provide safe, clean water to the entire world’s people. The world’s water resources are our lifeline for survival, and [or sustainable development in the 21st century. Together, we must manage them better.
单选题We had to learn chemical（）at school but I can only remember H2O for water.AprinciplesBprescriptionsCformulaDformulae