单选题Without the sun’s light _____ the earth’s surface, it would be so cold that life could not exist on the earth.A warmsB warmedC warmingD to warm
题目
单选题
Without the sun’s light _____ the earth’s surface, it would be so cold that life could not exist on the earth.
A
warms
B
warmed
C
warming
D
to warm
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更多“单选题Without the sun’s light _____ the earth’s surface, it would be so cold that life could not exist on the earth.A warmsB warmedC warmingD to warm”相关问题
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第1题：
共用题干
第三篇
“Life Form Found" on Saturn ' s Titan
Scientists 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,where
temperatures 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.答案：A解析：由文章第一段第二句话中“The discovery of...which pointed to the existence of methane- based form of life on Saturn' s biggest moon.”可知，科学家们的证据显示，土星的这个最大的卫 星上有甲烷基的生命形态存在，故选B。
由文章第二、三段的内容可知，科学家们发现有线索显示“土卫六”上原始的外星生物 在由氢气环绕的稠密大气层中“呼吸”，也就是说这个卫星上有氢气的消耗现象。故选D。
由文章前五段的内容可知，科学家在文章开头提出“土卫六”上可能有甲烷基的生命形 态，即methane-based life，接下来的内容给出了科学家们对此说法的一系列证据来进行论证，故 选C。
由文章的最后两段中Mark Allen的话，尤其是文章最后一句“It is more likely that a chemical process ,without biology , can explain these results.”可知，科学家们认为应该用化学过程 来解释为什么“土卫六”表面没有乙炔，故选B。
由文章内容可知，科学家们提出了土星的这个最大的行星上可能有一种不依赖于水的 生命形态，并从各方面进行了证明，故选A。第5部分：补全短文 -
第2题：
共用题干
第三篇
“Life Form Found" on Saturn ' s Titan
Scientists 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,where
temperatures 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 Titan
B:scientists agree that a chemical process is a convincing explanation
C:scientists share the opinion that a biological explanation is reasonable
D:scientists are arguing over whether there is life on Titan答案：B解析：由文章第一段第二句话中“The discovery of...which pointed to the existence of methane- based form of life on Saturn' s biggest moon.”可知，科学家们的证据显示，土星的这个最大的卫 星上有甲烷基的生命形态存在，故选B。
由文章第二、三段的内容可知，科学家们发现有线索显示“土卫六”上原始的外星生物 在由氢气环绕的稠密大气层中“呼吸”，也就是说这个卫星上有氢气的消耗现象。故选D。
由文章前五段的内容可知，科学家在文章开头提出“土卫六”上可能有甲烷基的生命形 态，即methane-based life，接下来的内容给出了科学家们对此说法的一系列证据来进行论证，故 选C。
由文章的最后两段中Mark Allen的话，尤其是文章最后一句“It is more likely that a chemical process ,without biology , can explain these results.”可知，科学家们认为应该用化学过程 来解释为什么“土卫六”表面没有乙炔，故选B。
由文章内容可知，科学家们提出了土星的这个最大的行星上可能有一种不依赖于水的 生命形态，并从各方面进行了证明，故选A。第5部分：补全短文 -
第3题：
At the first sight the planet Mars does not appear very welcome to any kind of life．It has very little oxygen and water,the temperature at night is below-50~Cand winds of 100 miles per hour cause severe dust storms．However,the surface of the planet seems to show that water flowed across it some time in the past,and it is believed that there is enough ice at the poles to cover the planet with water if it melts．Although there is no life on the Mars now,some scientists think that there may have been some form of life long time ago．At that time,the planet had active volcanoes;the atmosphere was thicker and warmer;and there was water．In fact,in some ways the Mars may have been similar to the Earth,where life exists.
Some people believe that the Mars could support life in the future if the right conditions were produced．The first step would be to warm the planet using certain gases which trap the Sun's heat in the planet's atmosphere．With warmth,water and carbon dioxide(二氧化碳),simple plants could begin to grow．These plants could slowly make the Mars more suitable for living．It is estimated that the whole process might take between 100,000 and 200,000 years．In the meantime,people could begin to live on the planet in special closed environments．They would provide a lot of useful information about conditions on the Mars and the problems connected with living there.
Which is the best title for this passage?A.The Possibility of Life on the Mars
B.Future Conditions on the Mars
C.The Mars and the Earth
D.A Study of the Climate of the Mars答案：A解析：文章的标题就是文章的中心。作者从火星上曾经有过生命的证明谈到未来通过提高温度而使火星适合生存的设想，表明文章的中心是：火星具有生命存在可能性。 -
第4题：
At the first sight the planet Mars does not appear very welcome to any kind of life．It has very little oxygen and water,the temperature at night is below-50~Cand winds of 100 miles per hour cause severe dust storms．However,the surface of the planet seems to show that water flowed across it some time in the past,and it is believed that there is enough ice at the poles to cover the planet with water if it melts．Although there is no life on the Mars now,some scientists think that there may have been some form of life long time ago．At that time,the planet had active volcanoes;the atmosphere was thicker and warmer;and there was water．In fact,in some ways the Mars may have been similar to the Earth,where life exists.
Some people believe that the Mars could support life in the future if the right conditions were produced．The first step would be to warm the planet using certain gases which trap the Sun's heat in the planet's atmosphere．With warmth,water and carbon dioxide(二氧化碳),simple plants could begin to grow．These plants could slowly make the Mars more suitable for living．It is estimated that the whole process might take between 100,000 and 200,000 years．In the meantime,people could begin to live on the planet in special closed environments．They would provide a lot of useful information about conditions on the Mars and the problems connected with living there.
The author's attitude towards the possibility of life on the Mars in the future is__.A.doubtful
B.positive
C.negative
D.uninterested答案：B解析：根据全文可以判断，作者对人类在火星上生存的可能性抱着积极、乐观的态度。 -
第5题：
共用题干
So Many"Earths"
The Milky Way（银河）contains billions of Earth-sized planets that could support life.That's the finding of a new study.It draws on data that came from NASA's top planet-hunting telescope.
A mechanical failure recently put that Kepler space telescope out of service.Kepler had played a big role in creating a census of planets orbiting some 170,000 stars.Its data have been helping astronomers predict how common planets are in our galaxy.The telescope focused on hunting planets that might have conditions similar to those on Earth.
The authors of a study,published in The Proceedings of the National Academy of Sciences,conclude that between 14 and 30 out of every 100 stars,with a mass and temperature similar to the Sun,may host a planet that could support life as we know it.Such a planet would have a diameter at least as large as Earth's,but no more than twice that big.The planet also would have to orbit in a star's habitable zone.That's where the surface temperature would allow any water to exist as a liquid.
The new estimate of how many planets might fit these conditions comes from studying more than 42,000 stars and identifying suitable worlds orbiting them.The scientists used those numbers to extrapolate（推算） to the rest of the stars that the telescope could not see.
The estimate is rough,the authors admit.If applied to the solar system,it would define as habitable a zone starting as close to the Sun as Venus and running to as far away as Mars.Neither planet is Earthlike (although either might have been in the distant past).Using tighter limits,the researchers estimate that between 4 and 8 out of every 100 sunlike stars could host an Earth-sized world.These are ones that would take 200 to 400 days to complete a yearly orbit.
Four out of every 100 sunlike stars doesn't sound like a big number.It would mean,however,that the Milky Way could host more than a billion Earth-sized planets with a chance for life.The planet that could support life might be a little bit smaller than Earth.
A:Right
B:Wrong
C:Not mentioned答案：B解析：本篇文章只在第二段第一句表明，近来一次机械故障使开普勒太空望远镜不再为我们服务，并没有提到开普勒太空望远镜为我们服务了多少年。
第二段最后一句表明，开普勒太空望远镜主要寻找与地球有相似环境的星球。
第三段第二句表明，可让生命存在的星球的直径至少与地球的直径一样大，但不会超过地球直径的两倍。由此可推测出其不会比地球小，因此题干表述错误。
第三段第三、四句表明，适合生命存在的星球必须与它所环绕的恒星有一个合适的距离，以保证星球表面的温度允许液态水存在，而地球正是适合人类居住的星球，而且地球是绕着太阳运行的。
第四段第一句表明，这项新评估源于对超过4.2万颗星球的分析，而非源于对17万颗星球的分析。
第五段第一句表明，研究者承认这项评估是粗糙的，即不精确的。
文章第一段指出，这次的调查结果是新的发现，但通篇文章并未提到这是对可能有生命存在的星球的首次研究。 -
第6题：
共用题干
So Many"Earths"
The Milky Way（银河）contains billions of Earth-sized planets that could support life.That's the finding of a new study.It draws on data that came from NASA's top planet-hunting telescope.
A mechanical failure recently put that Kepler space telescope out of service.Kepler had played a big role in creating a census of planets orbiting some 170,000 stars.Its data have been helping astronomers predict how common planets are in our galaxy.The telescope focused on hunting planets that might have conditions similar to those on Earth.
The authors of a study,published in The Proceedings of the National Academy of Sciences,conclude that between 14 and 30 out of every 100 stars,with a mass and temperature similar to the Sun,may host a planet that could support life as we know it.Such a planet would have a diameter at least as large as Earth's,but no more than twice that big.The planet also would have to orbit in a star's habitable zone.That's where the surface temperature would allow any water to exist as a liquid.
The new estimate of how many planets might fit these conditions comes from studying more than 42,000 stars and identifying suitable worlds orbiting them.The scientists used those numbers to extrapolate（推算） to the rest of the stars that the telescope could not see.
The estimate is rough,the authors admit.If applied to the solar system,it would define as habitable a zone starting as close to the Sun as Venus and running to as far away as Mars.Neither planet is Earthlike (although either might have been in the distant past).Using tighter limits,the researchers estimate that between 4 and 8 out of every 100 sunlike stars could host an Earth-sized world.These are ones that would take 200 to 400 days to complete a yearly orbit.
Four out of every 100 sunlike stars doesn't sound like a big number.It would mean,however,that the Milky Way could host more than a billion Earth-sized planets with a chance for life.The Earth is a planet orbiting in the Sun's habitable zone.
A:Right
B:Wrong
C:Not mentioned答案：A解析：本篇文章只在第二段第一句表明，近来一次机械故障使开普勒太空望远镜不再为我们服务，并没有提到开普勒太空望远镜为我们服务了多少年。
第二段最后一句表明，开普勒太空望远镜主要寻找与地球有相似环境的星球。
第三段第二句表明，可让生命存在的星球的直径至少与地球的直径一样大，但不会超过地球直径的两倍。由此可推测出其不会比地球小，因此题干表述错误。
第三段第三、四句表明，适合生命存在的星球必须与它所环绕的恒星有一个合适的距离，以保证星球表面的温度允许液态水存在，而地球正是适合人类居住的星球，而且地球是绕着太阳运行的。
第四段第一句表明，这项新评估源于对超过4.2万颗星球的分析，而非源于对17万颗星球的分析。
第五段第一句表明，研究者承认这项评估是粗糙的，即不精确的。
文章第一段指出，这次的调查结果是新的发现，但通篇文章并未提到这是对可能有生命存在的星球的首次研究。 -
第7题：
共用题干
Weight on and off the Earth We are so used to.our life on the surface of the earth that it can be quite an effort for our mind to break free of all the ideas that we take for granted.Because we can feel that things are heavy,we think of "weight"as being a fixed quality in an object,but it is not really fixed at all.If you could take a one-pound packet of butter 4,000 miles out from the earth,it would weigh only a quarter of a pound. Why would things weigh only a quarter as much as they do at the surface of the earth if we took them 4,000 miles out into space?The reason is this:all objects have a natural attraction for all other objects;this is called gravitational attraction.But this power of attraction between two obects gets weaker as they get farther apart.When the butter was at the surface of the earth,it was 4,000 miles from the center.When we took the butter 4,000 miles out,it was 8,000 miles from the center,which is twice the distance.If you double the distance between two objects,their gravitational attraction decreases two times two.If you treble the distance, it gets nine times weaker(three times three)and so on. So this is one of the first things we need to remember that the weight of an object in space is not the same as its weight on the surface of the earth. What about the weight of our pound of butter on the surface of the moon?At the distance the puii of the earth is about 4,000 times smaller than it is here on the surface,so we can forget all about the earth-pull on our butter. On the other hand,on the moon there will be an attraction between the butter and the moon,but the butter will weigh only about one-sixth as much as it does on the earth.This is because the moon is so much smaller than the earth.The amount of gravitational pull that a body produces depends on the amount of material in it.A packet of butter has a gravitational pull of its own;but this is very small in relation to the pull of something as large as the moon,or the earth,or the sun.We do not feel the gravitational pull of a packet of butter because
A:it is too small to have a gravitational pull of its own
B:its puil is so small that we tend to ignore it
C:its pui1 disappears in the presence of the earth's gravitation
D:it tends to melt and loses its gravitational puli答案：B解析：第一段最后一句表明，1磅重的黄油在离地球表面4000英里处重达0.25磅，第二段第一句也表明在4000英里高空处的物体重量仅为其在地球表面的重量的1/4。由此可推算出，4磅重的茶叶在离地球表面4000英里处重达1磅。
第一段第一句表明，我们之所以不能打破固有思维，是因为我们已经习惯了地球上的生活，也就是说，我们正是因为太过熟悉地球上的事物，才没有去质疑这些固有思维。
第一段第二句表明，物体的重量并非固定不变。第二段解释说，物体的重量源于物体间的引力。也就是说，物体的重量随着物体间引力的改变而改变。
最后一段第三句说明一个物体产生的引力与物体本身的重量有关。最后一段第四句又表明由于本身重量较小，一包黄油产生的引力很有限，相对于月球、地球、太阳等产生的强劲引力来说，比较容易被我们忽略。
本篇文章通篇讲的是重量是由引力产生的，并进一步阐述了物体间引力的变化、物体本身的重量，以及物体间的距离这三者之间的关系，主要讲的还是引力对重量的作用。 -
第8题：
共用题干
So Many"Earths"
The Milky Way（银河）contains billions of Earth-sized planets that could support life.That's the finding of a new study.It draws on data that came from NASA's top planet-hunting telescope.
A mechanical failure recently put that Kepler space telescope out of service.Kepler had played a big role in creating a census of planets orbiting some 170,000 stars.Its data have been helping astronomers predict how common planets are in our galaxy.The telescope focused on hunting planets that might have conditions similar to those on Earth.
The authors of a study,published in The Proceedings of the National Academy of Sciences,conclude that between 14 and 30 out of every 100 stars,with a mass and temperature similar to the Sun,may host a planet that could support life as we know it.Such a planet would have a diameter at least as large as Earth's,but no more than twice that big.The planet also would have to orbit in a star's habitable zone.That's where the surface temperature would allow any water to exist as a liquid.
The new estimate of how many planets might fit these conditions comes from studying more than 42,000 stars and identifying suitable worlds orbiting them.The scientists used those numbers to extrapolate（推算） to the rest of the stars that the telescope could not see.
The estimate is rough,the authors admit.If applied to the solar system,it would define as habitable a zone starting as close to the Sun as Venus and running to as far away as Mars.Neither planet is Earthlike (although either might have been in the distant past).Using tighter limits,the researchers estimate that between 4 and 8 out of every 100 sunlike stars could host an Earth-sized world.These are ones that would take 200 to 400 days to complete a yearly orbit.
Four out of every 100 sunlike stars doesn't sound like a big number.It would mean,however,that the Milky Way could host more than a billion Earth-sized planets with a chance for life.The main task of the Kepler space telescope is to find out planets with similar conditions to Earth's.
A:Right
B:Wrong
C:Not mentioned答案：A解析：本篇文章只在第二段第一句表明，近来一次机械故障使开普勒太空望远镜不再为我们服务，并没有提到开普勒太空望远镜为我们服务了多少年。
第二段最后一句表明，开普勒太空望远镜主要寻找与地球有相似环境的星球。
第三段第二句表明，可让生命存在的星球的直径至少与地球的直径一样大，但不会超过地球直径的两倍。由此可推测出其不会比地球小，因此题干表述错误。
第三段第三、四句表明，适合生命存在的星球必须与它所环绕的恒星有一个合适的距离，以保证星球表面的温度允许液态水存在，而地球正是适合人类居住的星球，而且地球是绕着太阳运行的。
第四段第一句表明，这项新评估源于对超过4.2万颗星球的分析，而非源于对17万颗星球的分析。
第五段第一句表明，研究者承认这项评估是粗糙的，即不精确的。
文章第一段指出，这次的调查结果是新的发现，但通篇文章并未提到这是对可能有生命存在的星球的首次研究。 -
第9题：
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?正确答案：
1.Water. 根据文中第二段,水只能表明生命存在的可能性,但不能证实。
2.Nitrogen. / The presence of nitrogen. 文中第九段第一句话很明确地告诉我们nitrogen would be a much clearer signature of life。
3.The search for water. 第七段最后一句话指出,在火星上通过搜索水来搜索生命的存在是不正确的。
4.The small amount (2% to 3%) of nitrogen in the Martian atmosphere . 文中第九段中提到火星上氮的含量很少可以表明目前火星上没有生命的存在。
5.Because current instruments aren’t very sensitive. 文中第十四段指出,由于现在的设备还不是那么敏感,所以不能够用来在太阳系的其他星球上探测生命。解析： 暂无解析 -
第10题：
单选题When the sun becomes a red giant, what will conditions be like on Earth?AIts atmosphere will freeze and become solid
BIt will be enveloped in the expanding surface of the sun.
CIt will become too hot for life to exist.
DIt will be nearly destroyed by nova explosions.
正确答案： A解析：
细节题。第二段描述最初太阳会发生的变化，该段倒数第二句指出在这一阶段太阳会变成红色的巨星，接下来最后一句提到“Temperatures on the Earth will become too hot for life to exist.”（地球上的温度会变得过热，以至于生命无法存活），故选C。 -
第11题：
单选题Only a small part of the sun’s energy reaches the earth’ s surface because most of it is ______.Aabsorbed by the clouds in the lower atmosphere
Breflected by the gases in the upper atmosphere
Clost in the upper and lower atmosphere
Dused to evaporate water from the oceans and lakes
正确答案： B解析：
根据第二段It is either reflected or absorbed by the gases in the upper atmosphere. Of the energy that reaches the lower atmosphere, 30% is reflected by clouds or the earth’s surface.太阳的多数能量是被高空中的大气反射或者吸收。因此B选项正确。 -
第12题：
单选题Without the sun’s light ______ the earth’s surface, it would be so cold that life could not exist on the earth.Awarms
Bwarmed
Cwarming
Dto warm
正确答案： D解析：
句意：没有阳光温暖地球表面，地球就会非常寒冷，生物就无法在地球上生存。Without加独立主格，分词的主语the sun’s light和warm之间应该是主动关系，用现在分词，故为C。 -
第13题：
共用题干
第三篇
“Life Form Found" on Saturn ' s Titan
Scientists 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,where
temperatures 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.答案：D解析：由文章第一段第二句话中“The discovery of...which pointed to the existence of methane- based form of life on Saturn' s biggest moon.”可知，科学家们的证据显示，土星的这个最大的卫 星上有甲烷基的生命形态存在，故选B。
由文章第二、三段的内容可知，科学家们发现有线索显示“土卫六”上原始的外星生物 在由氢气环绕的稠密大气层中“呼吸”，也就是说这个卫星上有氢气的消耗现象。故选D。
由文章前五段的内容可知，科学家在文章开头提出“土卫六”上可能有甲烷基的生命形 态，即methane-based life，接下来的内容给出了科学家们对此说法的一系列证据来进行论证，故 选C。
由文章的最后两段中Mark Allen的话，尤其是文章最后一句“It is more likely that a chemical process ,without biology , can explain these results.”可知，科学家们认为应该用化学过程 来解释为什么“土卫六”表面没有乙炔，故选B。
由文章内容可知，科学家们提出了土星的这个最大的行星上可能有一种不依赖于水的 生命形态，并从各方面进行了证明，故选A。第5部分：补全短文 -
第14题：
Mercury’s（ ）is so much greater than the Earth’s that it completes more than four revolutions around the Sun in the time it takes the Earth to complete one.A.velocity
B.orbit
C.weight
D.diameter答案：A解析：A选项意为“速度，速率”；B选项意为“轨道，活动范围”；C选项意为“重量，重要性，影响力”；D选项意为“直径，（透镜等的）倍率”。根据题意答案为A。 -
第15题：
At the first sight the planet Mars does not appear very welcome to any kind of life．It has very little oxygen and water,the temperature at night is below-50~Cand winds of 100 miles per hour cause severe dust storms．However,the surface of the planet seems to show that water flowed across it some time in the past,and it is believed that there is enough ice at the poles to cover the planet with water if it melts．Although there is no life on the Mars now,some scientists think that there may have been some form of life long time ago．At that time,the planet had active volcanoes;the atmosphere was thicker and warmer;and there was water．In fact,in some ways the Mars may have been similar to the Earth,where life exists.
Some people believe that the Mars could support life in the future if the right conditions were produced．The first step would be to warm the planet using certain gases which trap the Sun's heat in the planet's atmosphere．With warmth,water and carbon dioxide(二氧化碳),simple plants could begin to grow．These plants could slowly make the Mars more suitable for living．It is estimated that the whole process might take between 100,000 and 200,000 years．In the meantime,people could begin to live on the planet in special closed environments．They would provide a lot of useful information about conditions on the Mars and the problems connected with living there.
There could be life on the Mars in the future ifA.it supported life in the past
B.certain gases are used to cool the planet
C.the atmosphere can be heated enough to grow simple plants
D.the planet's volcanoes become as active as they were in the past答案：C解析：第二段大意是：如果要想改变火星的条件使之适合居住，首先要提高星球的温度，其方法是用某些气体收集太阳的热能。有了温度、水和二氧化碳，一些植物便可生长。慢慢地使星球适合生存。选项C，“人们可以以提高环境的温度的方式来使一些植物生长”是正确的。 -
第16题：
At the first sight the planet Mars does not appear very welcome to any kind of life．It has very little oxygen and water,the temperature at night is below-50~Cand winds of 100 miles per hour cause severe dust storms．However,the surface of the planet seems to show that water flowed across it some time in the past,and it is believed that there is enough ice at the poles to cover the planet with water if it melts．Although there is no life on the Mars now,some scientists think that there may have been some form of life long time ago．At that time,the planet had active volcanoes;the atmosphere was thicker and warmer;and there was water．In fact,in some ways the Mars may have been similar to the Earth,where life exists.
Some people believe that the Mars could support life in the future if the right conditions were produced．The first step would be to warm the planet using certain gases which trap the Sun's heat in the planet's atmosphere．With warmth,water and carbon dioxide(二氧化碳),simple plants could begin to grow．These plants could slowly make the Mars more suitable for living．It is estimated that the whole process might take between 100,000 and 200,000 years．In the meantime,people could begin to live on the planet in special closed environments．They would provide a lot of useful information about conditions on the Mars and the problems connected with living there.
Some scientists think there may have been life on the Mars in the past because__.A.there is no life there now
B.there is a large amount of water at the poles
C.the Mars may be able to support life in the future
D.conditions may have been similar to those on the Earth答案：D解析：第一段大意是：人们最初对火星的印象是火星上不可能有生命。因为几乎没有氧气和水，并且夜间温度低于-50°C，同时还有每小时l00英里的风速引起的严重的沙尘暴。然而星球的表面却告诉我们，过去的某个时段水曾经从这里流过。人们相信极地有足够的冰，一旦融化便可覆盖整个星球。虽然现在火星上没有生命，但在过去很久很久以前，生命很有可能存在过。由此可看出，生命所需的条件——水和氧——在火星上和在地球上是相似的。所以选项D正确。而选项B说火星上有水是不对的。火星的极地有冰，只有当冰融化后才能使整个星球有水。 -
第17题：
共用题干
So Many"Earths"
The Milky Way（银河）contains billions of Earth-sized planets that could support life.That's the finding of a new study.It draws on data that came from NASA's top planet-hunting telescope.
A mechanical failure recently put that Kepler space telescope out of service.Kepler had played a big role in creating a census of planets orbiting some 170,000 stars.Its data have been helping astronomers predict how common planets are in our galaxy.The telescope focused on hunting planets that might have conditions similar to those on Earth.
The authors of a study,published in The Proceedings of the National Academy of Sciences,conclude that between 14 and 30 out of every 100 stars,with a mass and temperature similar to the Sun,may host a planet that could support life as we know it.Such a planet would have a diameter at least as large as Earth's,but no more than twice that big.The planet also would have to orbit in a star's habitable zone.That's where the surface temperature would allow any water to exist as a liquid.
The new estimate of how many planets might fit these conditions comes from studying more than 42,000 stars and identifying suitable worlds orbiting them.The scientists used those numbers to extrapolate（推算） to the rest of the stars that the telescope could not see.
The estimate is rough,the authors admit.If applied to the solar system,it would define as habitable a zone starting as close to the Sun as Venus and running to as far away as Mars.Neither planet is Earthlike (although either might have been in the distant past).Using tighter limits,the researchers estimate that between 4 and 8 out of every 100 sunlike stars could host an Earth-sized world.These are ones that would take 200 to 400 days to complete a yearly orbit.
Four out of every 100 sunlike stars doesn't sound like a big number.It would mean,however,that the Milky Way could host more than a billion Earth-sized planets with a chance for life.The new finding is based on a thorough study of 170,000 stars in the Milky Way.
A:Right
B:Wrong
C:Not mentioned答案：B解析：本篇文章只在第二段第一句表明，近来一次机械故障使开普勒太空望远镜不再为我们服务，并没有提到开普勒太空望远镜为我们服务了多少年。
第二段最后一句表明，开普勒太空望远镜主要寻找与地球有相似环境的星球。
第三段第二句表明，可让生命存在的星球的直径至少与地球的直径一样大，但不会超过地球直径的两倍。由此可推测出其不会比地球小，因此题干表述错误。
第三段第三、四句表明，适合生命存在的星球必须与它所环绕的恒星有一个合适的距离，以保证星球表面的温度允许液态水存在，而地球正是适合人类居住的星球，而且地球是绕着太阳运行的。
第四段第一句表明，这项新评估源于对超过4.2万颗星球的分析，而非源于对17万颗星球的分析。
第五段第一句表明，研究者承认这项评估是粗糙的，即不精确的。
文章第一段指出，这次的调查结果是新的发现，但通篇文章并未提到这是对可能有生命存在的星球的首次研究。 -
第18题：
共用题干
Weight on and off the Earth We are so used to.our life on the surface of the earth that it can be quite an effort for our mind to break free of all the ideas that we take for granted.Because we can feel that things are heavy,we think of "weight"as being a fixed quality in an object,but it is not really fixed at all.If you could take a one-pound packet of butter 4,000 miles out from the earth,it would weigh only a quarter of a pound. Why would things weigh only a quarter as much as they do at the surface of the earth if we took them 4,000 miles out into space?The reason is this:all objects have a natural attraction for all other objects;this is called gravitational attraction.But this power of attraction between two obects gets weaker as they get farther apart.When the butter was at the surface of the earth,it was 4,000 miles from the center.When we took the butter 4,000 miles out,it was 8,000 miles from the center,which is twice the distance.If you double the distance between two objects,their gravitational attraction decreases two times two.If you treble the distance, it gets nine times weaker(three times three)and so on. So this is one of the first things we need to remember that the weight of an object in space is not the same as its weight on the surface of the earth. What about the weight of our pound of butter on the surface of the moon?At the distance the puii of the earth is about 4,000 times smaller than it is here on the surface,so we can forget all about the earth-pull on our butter. On the other hand,on the moon there will be an attraction between the butter and the moon,but the butter will weigh only about one-sixth as much as it does on the earth.This is because the moon is so much smaller than the earth.The amount of gravitational pull that a body produces depends on the amount of material in it.A packet of butter has a gravitational pull of its own;but this is very small in relation to the pull of something as large as the moon,or the earth,or the sun.According to the passage,"weight"should be understood in the sense that
A:it is fixed if it is outside the earth's gravitational puli
B:it decreases four times when it is 4,000 miles from the earth's center
C:it varies with the change of the gravitational attraction between two objects
D:things increase in amount as they are closer to the earth's surface答案：C解析：第一段最后一句表明，1磅重的黄油在离地球表面4000英里处重达0.25磅，第二段第一句也表明在4000英里高空处的物体重量仅为其在地球表面的重量的1/4。由此可推算出，4磅重的茶叶在离地球表面4000英里处重达1磅。
第一段第一句表明，我们之所以不能打破固有思维，是因为我们已经习惯了地球上的生活，也就是说，我们正是因为太过熟悉地球上的事物，才没有去质疑这些固有思维。
第一段第二句表明，物体的重量并非固定不变。第二段解释说，物体的重量源于物体间的引力。也就是说，物体的重量随着物体间引力的改变而改变。
最后一段第三句说明一个物体产生的引力与物体本身的重量有关。最后一段第四句又表明由于本身重量较小，一包黄油产生的引力很有限，相对于月球、地球、太阳等产生的强劲引力来说，比较容易被我们忽略。
本篇文章通篇讲的是重量是由引力产生的，并进一步阐述了物体间引力的变化、物体本身的重量，以及物体间的距离这三者之间的关系，主要讲的还是引力对重量的作用。 -
第19题：
共用题干
So Many"Earths"
The Milky Way（银河）contains billions of Earth-sized planets that could support life.That's the finding of a new study.It draws on data that came from NASA's top planet-hunting telescope.
A mechanical failure recently put that Kepler space telescope out of service.Kepler had played a big role in creating a census of planets orbiting some 170,000 stars.Its data have been helping astronomers predict how common planets are in our galaxy.The telescope focused on hunting planets that might have conditions similar to those on Earth.
The authors of a study,published in The Proceedings of the National Academy of Sciences,conclude that between 14 and 30 out of every 100 stars,with a mass and temperature similar to the Sun,may host a planet that could support life as we know it.Such a planet would have a diameter at least as large as Earth's,but no more than twice that big.The planet also would have to orbit in a star's habitable zone.That's where the surface temperature would allow any water to exist as a liquid.
The new estimate of how many planets might fit these conditions comes from studying more than 42,000 stars and identifying suitable worlds orbiting them.The scientists used those numbers to extrapolate（推算） to the rest of the stars that the telescope could not see.
The estimate is rough,the authors admit.If applied to the solar system,it would define as habitable a zone starting as close to the Sun as Venus and running to as far away as Mars.Neither planet is Earthlike (although either might have been in the distant past).Using tighter limits,the researchers estimate that between 4 and 8 out of every 100 sunlike stars could host an Earth-sized world.These are ones that would take 200 to 400 days to complete a yearly orbit.
Four out of every 100 sunlike stars doesn't sound like a big number.It would mean,however,that the Milky Way could host more than a billion Earth-sized planets with a chance for life.This is the first research finding about the planets with a chance for life.
A:Right
B:Wrong
C:Not mentioned答案：C解析：本篇文章只在第二段第一句表明，近来一次机械故障使开普勒太空望远镜不再为我们服务，并没有提到开普勒太空望远镜为我们服务了多少年。
第二段最后一句表明，开普勒太空望远镜主要寻找与地球有相似环境的星球。
第三段第二句表明，可让生命存在的星球的直径至少与地球的直径一样大，但不会超过地球直径的两倍。由此可推测出其不会比地球小，因此题干表述错误。
第三段第三、四句表明，适合生命存在的星球必须与它所环绕的恒星有一个合适的距离，以保证星球表面的温度允许液态水存在，而地球正是适合人类居住的星球，而且地球是绕着太阳运行的。
第四段第一句表明，这项新评估源于对超过4.2万颗星球的分析，而非源于对17万颗星球的分析。
第五段第一句表明，研究者承认这项评估是粗糙的，即不精确的。
文章第一段指出，这次的调查结果是新的发现，但通篇文章并未提到这是对可能有生命存在的星球的首次研究。 -
第20题：
共用题干
So Many"Earths"
The Milky Way（银河）contains billions of Earth-sized planets that could support life.That's the finding of a new study.It draws on data that came from NASA's top planet-hunting telescope.
A mechanical failure recently put that Kepler space telescope out of service.Kepler had played a big role in creating a census of planets orbiting some 170,000 stars.Its data have been helping astronomers predict how common planets are in our galaxy.The telescope focused on hunting planets that might have conditions similar to those on Earth.
The authors of a study,published in The Proceedings of the National Academy of Sciences,conclude that between 14 and 30 out of every 100 stars,with a mass and temperature similar to the Sun,may host a planet that could support life as we know it.Such a planet would have a diameter at least as large as Earth's,but no more than twice that big.The planet also would have to orbit in a star's habitable zone.That's where the surface temperature would allow any water to exist as a liquid.
The new estimate of how many planets might fit these conditions comes from studying more than 42,000 stars and identifying suitable worlds orbiting them.The scientists used those numbers to extrapolate（推算） to the rest of the stars that the telescope could not see.
The estimate is rough,the authors admit.If applied to the solar system,it would define as habitable a zone starting as close to the Sun as Venus and running to as far away as Mars.Neither planet is Earthlike (although either might have been in the distant past).Using tighter limits,the researchers estimate that between 4 and 8 out of every 100 sunlike stars could host an Earth-sized world.These are ones that would take 200 to 400 days to complete a yearly orbit.
Four out of every 100 sunlike stars doesn't sound like a big number.It would mean,however,that the Milky Way could host more than a billion Earth-sized planets with a chance for life.The estimate of the number of planets that could support life is not very accurate.
A:Right
B:Wrong
C:Not mentioned答案：A解析：本篇文章只在第二段第一句表明，近来一次机械故障使开普勒太空望远镜不再为我们服务，并没有提到开普勒太空望远镜为我们服务了多少年。
第二段最后一句表明，开普勒太空望远镜主要寻找与地球有相似环境的星球。
第三段第二句表明，可让生命存在的星球的直径至少与地球的直径一样大，但不会超过地球直径的两倍。由此可推测出其不会比地球小，因此题干表述错误。
第三段第三、四句表明，适合生命存在的星球必须与它所环绕的恒星有一个合适的距离，以保证星球表面的温度允许液态水存在，而地球正是适合人类居住的星球，而且地球是绕着太阳运行的。
第四段第一句表明，这项新评估源于对超过4.2万颗星球的分析，而非源于对17万颗星球的分析。
第五段第一句表明，研究者承认这项评估是粗糙的，即不精确的。
文章第一段指出，这次的调查结果是新的发现，但通篇文章并未提到这是对可能有生命存在的星球的首次研究。 -
第21题：
单选题The greatest chance for the existence of extraterrestrial life is on a planet beyond our solar system. The Milky Way galaxy alone contains 100 billion other suns, many of which could be accompanied by planets similar enough to Earth to make them suitable abodes of life. The statement above assumes which of the following?ALiving creatures on another planet would probably have the same appearance as those on Earth.
BLife cannot exist on other planets in our solar system.
CIf the appropriate physical conditions exist, life is an inevitable consequence.
DMore than one of the suns in the galaxy is accompanied by an Earth-like planet.
EIt is likely that life on another planet would require conditions similar to those on Earth.
正确答案： E解析：
文段从其他行星与地球环境相似，推出其他行星上有生命存在的结论，所以可知作者暗示生命体的存在需要和地球相类似的生存条件，故本题应选E项。 -
第22题：
填空题Earth would not have developed without the Sun.____正确答案： B解析：
根据题干信息“developed without”可以定位到B段“Life on Earth could not exist without the Sun, and the planet itself would not have developed without it”，如果没有太阳，地球上的生命将不会存在，地球本身也不会发展到现在，太阳是地球存在发展的条件，题干中的“Earth”即指原文中的“the planet itself”，故匹配段落为B。 -
第23题：
单选题We learn from the passage that ______.Aall living things on the earth depend on the sun for their food
Ba forest looks dark in winter because it absorbs solar energy
Conly 0.023 of the energy from the sun is made use of on the earth
Dgreenhouse gases allow heat energy to escape from the earth’ s surface
正确答案： A解析：
根据第一段Sunlight also provides the energy used by green plants to make their own food，阳光给绿色植物提供能量使其生产自己的食物，故选A。 -
第24题：
单选题Planetary aberration is due，in part，to（）.Arefraction of light as it enters the Earth's atmosphere
Brotation of the Earth on it's axis
Cthe body's orbital motion during the time required for its light to reach Earth
Da false horizon
正确答案： A解析： 暂无解析