If there were life on Mars, such life forms()unable to survive on earthAisBareCwould beDwill be

If there were life on Mars, such life forms()unable to survive on earth

Ais

Bare

Cwould be

Dwill be


参考解析

相关考题:

If there were life on Mars, such life forms( )unable to survive on earth. A、isB、areC、would beD、will be

According to Paragraph 4, what’s Jovce’s opinion about life in 1900? [ ]A There were fewer problems for the familyB Life was simpler but worse than it is nowC There were things she liked and dislikedD The family had more time to stay together

For threequarters of its span on Earth, life evolved almost _______ as microorganisms.A precisely B instantly C initially D exclusively

Part BDirections: The following paragraphs are given in a wrong order. For Questions 41—45, you are required to reorganize these paragraphs into a coherent article by choosing from the list A - G to fill in each numbered box. The first and the last paragraphs have been placed for you in Boxes. Mark your answers on ANSWER SHEET 1. ( 10 points)[A] These issues cut right across traditional religious dogma. Many people cling to the belief that the origin of life required a unique divine act. But ff life on Earth is not unique, the case for a miraculous origin would be undermined. The discovery of even a humble bacterium on Mars, if it could be shown to have arisen independently from Earth life would support the view that life emerges naturally.[B] Contrary to popular belief, speculation that we are not alone in the universe is as old as philosophy itself. The essential steps in the reasoning were based on the atomic theory of the ancient Greek philosopher Democritus. First, the laws of nature are universal. Second, there is nothing special or privileged about Earth. Finally, if something is possible, nature tends to make it happen. Philosophy is one thing, filling in the physical details is another. Although astronomers increasingly suspect that bio-friendly planets may be abundant in the universe, the chemical steps leading to life remain largely mysterious.[C] There is, however, a contrary view-one that is gaining strength and directly challenges orthodox biology. It is that complexity can emerge spontaneously through a process of self-organization, ff matter and energy have an inbuilt tendency to amplify and channel organized complexity, the odds against the formation of life and the subsequent evolution of intelligence could be drastically shortened. The relevance of self- organization to biology remains hotly debated. It suggests, however, that although the universe as a whole may be dying, an opposite, progressive trend may also exist as a fundamental property of nature. The emergence of extraterrestrial life, particularly-intelligent life, is a key test for these rival paradigms.[D] Similar reasoning applies to evolution. According to the orthodox view, Darwinian selection is utterly blind. Any impression that the transition from microbes to man represents progress is pure chauvinism of our part. The path of evolution is merely a random walk through the realm of possibilities. If this is right, there can be no directionality, no innate drive forward; in particular, no push toward consciousness and intelligence. Should Earth be struck by an asteroid, destroying all higher life -forms, intelligent beings, still less humanoids, would almost certainly not arise next time around.[E] Traditionally, biologists believed that life is a freak-the result of a zillion - to - on accidental concatenation of molecules. It follows that the likelihood of its happening again elsewhere in the cosmos is infinitesimal. This viewpoint de- rives from the second law of thermodynamics, which predicts that the universe is dying - slowly and inexorably degenerating toward a state of total chaos. Life stumbles across this trend only because it is a pure statistical luck.[F] Historically, the Roman Catholic church regarded any discussion of alien life as heresy. Speculating about other inhabited worlds was one reason philosopher Giordano Bruno was burned at the stake in 1600. Belief that mankind has-a special relationship with God is central to the monotheistic religions. The existence of alien beings, especially if they were further advanced than humans intellectually and spiritually, would disrupt this cozy view.[G] The discovery of life beyond earth would transform. not only our science but also our religions, our belief systems and our entire world view. For in a sense, the search for extraterrestrial life is really a search for ourselves - who we are and what our place is in the grand sweep of the cosmos.Order:41___________________

共用题干To Survive or to Vanish1.Over 3.6 billion years ago,the first creature was born in the world.Since then,the earth started its era with life.The history of life on earth has been a history of interaction between living things and their surroundings.To a large extent,the physical form and the habits of the earth's vegetation and its animal life have been molded by the environment. Considering the whole span of earthly time,the opposite effect,in which life actually modifies its surroundings,has been relatively slight. Only in the present century has one species一man acquired significant power to alter the nature of his world.2.During the past 25 years,this power has not only become increasingly great but it has changed in character. The most alarming of all man's assaults upon the environment is the contamination of air,earth,rivers,and sea with dangerous and even lethal materials. This pollution is for the most part irrecoverable.In this now universal contamination of the environment,chemicals are the sinister partners of radiation in changing the very nature of the world the very nature of its life. Chemicals sprayed on croplands or forests or gardens lie long in soil,entering into living organisms, passing from one to another in a chain of poisoning and death.Or they pass mysteriously by underground streams until they emerge and combine into new forms that kill vegetation,sicken cattle,and work unknown harm on those who drink from once pure wells."Man can hardly even recognize the devils of his own creation,"as a scientist has said.3.Hundreds of millions of years have passed before the globe produced the life that now inhabits the earth.Given time not in years but in millennia life adjusts,and a balance has been reached.But in the modern world there is no time.4.The quick steps of change follows the impetuous pace of man rather than the deliberate pace of nature.Radiation is now the unnatural creation of man's tampering with the atom.The chemicals are the synthetic creations of man's inventive mind,having no counterparts in nature.5.To survive these chemicals would require not merely the years of one man's life but the life of generations.And even this,were it by some miracle possible,would be futile,for the new chemicals come from our laboratories in an endless stream;almost five hundred annually find their way into actual use in the United States alone.Among them are many that are used in man's war against nature.Since the mid l940's over 200 basic chemicals have been created for use in killing insects,weeds,and other organisms described as"pests".6.It is not my contention that chemical insecticides must never he used.I do contend that we have put poisonous and biologically potent chemicals indiscriminately into the hands of persons largely or wholly ignorant of their potentials for harm. We have subjected enormous numbers of people to contact with these poisons,without their consent and often without their knowledge.I contend,furthermore,that we have allowed these chemicals to be used with little or no advance investigation of their effect on soil,water,wildlife,and man himself. Future generations are unlikely to forgive our lack of concern for the integrity of the natural world that supports all life.Human's pollution on nature is for the most part_______.A:man's tampering with the atomB:enormous numbers of people to contact with these poisonsC:the integrity of the natural world that supports all lifeD:inventiveE:irrecoverableF:relatively slight

共用题干To Survive or to Vanish1.Over 3.6 billion years ago,the first creature was born in the world.Since then,the earth started its era with life.The history of life on earth has been a history of interaction between living things and their surroundings.To a large extent,the physical form and the habits of the earth's vegetation and its animal life have been molded by the environment. Considering the whole span of earthly time,the opposite effect,in which life actually modifies its surroundings,has been relatively slight. Only in the present century has one species一man acquired significant power to alter the nature of his world.2.During the past 25 years,this power has not only become increasingly great but it has changed in character. The most alarming of all man's assaults upon the environment is the contamination of air,earth,rivers,and sea with dangerous and even lethal materials. This pollution is for the most part irrecoverable.In this now universal contamination of the environment,chemicals are the sinister partners of radiation in changing the very nature of the world the very nature of its life. Chemicals sprayed on croplands or forests or gardens lie long in soil,entering into living organisms, passing from one to another in a chain of poisoning and death.Or they pass mysteriously by underground streams until they emerge and combine into new forms that kill vegetation,sicken cattle,and work unknown harm on those who drink from once pure wells."Man can hardly even recognize the devils of his own creation,"as a scientist has said.3.Hundreds of millions of years have passed before the globe produced the life that now inhabits the earth.Given time not in years but in millennia life adjusts,and a balance has been reached.But in the modern world there is no time.4.The quick steps of change follows the impetuous pace of man rather than the deliberate pace of nature.Radiation is now the unnatural creation of man's tampering with the atom.The chemicals are the synthetic creations of man's inventive mind,having no counterparts in nature.5.To survive these chemicals would require not merely the years of one man's life but the life of generations.And even this,were it by some miracle possible,would be futile,for the new chemicals come from our laboratories in an endless stream;almost five hundred annually find their way into actual use in the United States alone.Among them are many that are used in man's war against nature.Since the mid l940's over 200 basic chemicals have been created for use in killing insects,weeds,and other organisms described as"pests".6.It is not my contention that chemical insecticides must never he used.I do contend that we have put poisonous and biologically potent chemicals indiscriminately into the hands of persons largely or wholly ignorant of their potentials for harm. We have subjected enormous numbers of people to contact with these poisons,without their consent and often without their knowledge.I contend,furthermore,that we have allowed these chemicals to be used with little or no advance investigation of their effect on soil,water,wildlife,and man himself. Future generations are unlikely to forgive our lack of concern for the integrity of the natural world that supports all life.The effect of life modifying its surroundings has been_______.A:man's tampering with the atomB:enormous numbers of people to contact with these poisonsC:the integrity of the natural world that supports all lifeD:inventiveE:irrecoverableF:relatively slight

共用题干To Survive or to Vanish1.Over 3.6 billion years ago,the first creature was born in the world.Since then,the earth started its era with life.The history of life on earth has been a history of interaction between living things and their surroundings.To a large extent,the physical form and the habits of the earth's vegetation and its animal life have been molded by the environment. Considering the whole span of earthly time,the opposite effect,in which life actually modifies its surroundings,has been relatively slight. Only in the present century has one species一man acquired significant power to alter the nature of his world.2.During the past 25 years,this power has not only become increasingly great but it has changed in character. The most alarming of all man's assaults upon the environment is the contamination of air,earth,rivers,and sea with dangerous and even lethal materials. This pollution is for the most part irrecoverable.In this now universal contamination of the environment,chemicals are the sinister partners of radiation in changing the very nature of the world the very nature of its life. Chemicals sprayed on croplands or forests or gardens lie long in soil,entering into living organisms, passing from one to another in a chain of poisoning and death.Or they pass mysteriously by underground streams until they emerge and combine into new forms that kill vegetation,sicken cattle,and work unknown harm on those who drink from once pure wells."Man can hardly even recognize the devils of his own creation,"as a scientist has said.3.Hundreds of millions of years have passed before the globe produced the life that now inhabits the earth.Given time not in years but in millennia life adjusts,and a balance has been reached.But in the modern world there is no time.4.The quick steps of change follows the impetuous pace of man rather than the deliberate pace of nature.Radiation is now the unnatural creation of man's tampering with the atom.The chemicals are the synthetic creations of man's inventive mind,having no counterparts in nature.5.To survive these chemicals would require not merely the years of one man's life but the life of generations.And even this,were it by some miracle possible,would be futile,for the new chemicals come from our laboratories in an endless stream;almost five hundred annually find their way into actual use in the United States alone.Among them are many that are used in man's war against nature.Since the mid l940's over 200 basic chemicals have been created for use in killing insects,weeds,and other organisms described as"pests".6.It is not my contention that chemical insecticides must never he used.I do contend that we have put poisonous and biologically potent chemicals indiscriminately into the hands of persons largely or wholly ignorant of their potentials for harm. We have subjected enormous numbers of people to contact with these poisons,without their consent and often without their knowledge.I contend,furthermore,that we have allowed these chemicals to be used with little or no advance investigation of their effect on soil,water,wildlife,and man himself. Future generations are unlikely to forgive our lack of concern for the integrity of the natural world that supports all life.Paragraph 1_______A:Man should be cautious in chemical use.B:It takes generations for mankind to adapt themselves to the chemicals.C:Chemicals are human's inventionD:Human's power increases and has changed its character in the past quarter century.E:The new change in the relationship between earth and its creature一human's power playing a greater role in changing the worldF: Modern world gives no time for nature to adjust to human.

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 MarsB.Future Conditions on the MarsC.The Mars and the EarthD.A Study of the Climate of the Mars

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 pastB.certain gases are used to cool the planetC.the atmosphere can be heated enough to grow simple plantsD.the planet's volcanoes become as active as they were in the past

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.doubtfulB.positiveC.negativeD.uninterested

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 nowB.there is a large amount of water at the polesC.the Mars may be able to support life in the futureD.conditions may have been similar to those on the Earth

Starting with the______that there is life on the planet Mars, the scientist went on to develop his argument.A.foundationB.presentationC.premiseD.pretext

共用题干第一篇An Expensive MistakeIs there water on the planet Mars? Is there life on Mars?Was there ever life on Mars?Scientists from NASA wanted to know the answers to tliese questions.They built a spacecraft to travel around Mars and get informnation.The spacecraft was called the Mars Climate orbiter.The Mars Climate Orbiter left for Mars iii December 1998.The trip took nine and a half months.At first, everything was fine.However.when the Orbiter got near Mars,something terrible happened.The spacecraft didn't go to the right place.It went too close to Mars.it was too hot for the Orbiter there.The spacecraft couldn't function correctly.Suddenly,it stopped sending messages to NASA.The Orbiter was lost.How could this terrible thing happen? How did the Orbiter get closer to Mars than the scientists planned? Finally,they found the anlswer. Two teams of scientists worked together on the Orbiter. One team was in England,and one teann was in the United States.There were many similarities in the way they worked,but there was one important difference:The teams used different guidelines for measuring things.The United States team used the metric systcnni(公制).The oilier team used the English system.Because they used different systems,the scientists made a mathematical mistake.The Orbiter's orbit (the shape and pattern of its path)around Mars was not correct.The scientists put the Orbiter on the wrong path.The Orbiter got too close amid too hot,and it stopped functioning.Why didn'tanybody see the mistake before it was too late?Many things contributed to the problem. One thing was that NASA scientists and mathematicians were working on two other spacecrafts at the same time.This was a challenge,and they were very tired from working long hours.The Mars Climate Orbiter cost $94 million to build.It also cost a lot of money to try to find the lost Or- biter in space.In addition,NASA's research on the cause of the problem was very expensive.This wasn't the first time that two different measurement systems caused mistakes in scientific projects.However,the Mars Climate Orbiter was definitely the most expensive mistake of all!NASA built the Mars Climate Orbiter to get information about_______.A:the size of MarsB:possible life on MarsC:the shape of MarsD:the atmosphere of Mars

共用题干An Expensive MistakeIs there water on the planet Mars?Is there life in Mars? Was there ever life on Mars? Scientists from NASA wanted to know the answers to these questions.They built a space-craft to travel around Mars and get information.The spacecraft was called the Mars Climate Orbiter.The Mars Climate Orbiter left for Mars in December 1998.The trip took nine and a half months.At first,everything was fine.However,when the Orbiter got near Mars,something terrible happened.The spacecraft didn't go to the right place.It went too close to Mars.It was too hot for the Orbiter there.The spacecraft couldn't function correctly.Suddenly,it stopped sending messages to NASA.The Orbiter was lost.How could this terrible thing happen? How did the Orbiter get closer to Mars than the scientists planned?Finally,they found the answer.Two teams of scientists worked together on the Orbiter.One team was in England,and one team was in United States.There were many similarities in the way they worked,but there was one important difference:The teams used different guidelines for measuring things.The United States team used the metric system(公制).The other team used the English system.Because they used different systems,the scientists made a mathematical mistake.The Orbiter's orbit(the shape and pattern of its path)around Mars was not correct.The scientists put the Orbiter on the wrong path.The Orbiter got too close and too hot.And it stopped functioning.Why didn't anybody see the mistake before it was too late? Many things contributed to the problem.One thing was that NASA scientists and mathematicians were working on two other spacecrafts at the same time.This was a challenge,and they were very tired from working long hours.The Mars Climate Orbiter cost$94 million to build.It also cost a lot of money to try to find the lost Orbiter in space.In addition,NASA's research on the cause of the problem was very expensive.This wasn't the first time that two different measurement systems caused mistakes in scientific projects.However,the Mars Climate Orbiter was definitely the most expensive mistake of all!When did the Orbiter's problem begin?A:Right after it left for Mars.B:When it got near Mars.C:Right after it landed on Mars.D:When it returned to Earth.

单选题Starting with the _____ that there is life on the planet Mars, the scientist went on to develop his argument.ApremiseBpretextCfoundationDpresentation

单选题Stephen Hawking believes that earth is unlikely to be the only planet ______ life has developed gradually.AthatBwhereCwhichDwhose

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.

问答题Practice 6  Then came the First World War and the Second World War. (1) After each war, new ideas, new attitudes, new trades and occupations were revealed to villagers. The long-established order of society was no longer taken for granted. Electricity and the motorcar were steadily operating to make “village life” and “town life” almost alike. (2) Now with the highly developed science and technology and high-level social welfare for all, there is no point whatever in talking any longer about “village life.” It is just life, and that a better life.

问答题For centuries, explorers have risked their lives venturing into the unknown for reasons that were to varying degrees economic and nationalistic. Columbus went west to look for better trade routes to the Orient and to promote the greater glory of Spain, Lewis and Clark journeyed into the American wilderness to find out what the U.S. had acquired when it purchased Louisiana, and the Apollo astronauts rocketed to the moon in a dramatic show of technological muscle during the cold war.  Although their missions blended commercial and political-military imperatives, the explorers involved all accomplished some significant science by going where no scientists had gone before.  Today Mars looms as humanity’s next great terra incognita. And with doubtful prospects for a short-term financial return, with the cold war a rapidly fading memory and amid a growing emphasis on international cooperation in large space ventures, it is clear that imperatives other than profits or nationalism will have to compel human beings to leave their tracks on the planet’s reddish surface. Could it be that science, which has long played a minor role in exploration, is at last destined to take a leading role? The question naturally invites a couple of others; Are there experiment that only human could do on Mars? Could those experiments provide insights profound enough to justify the expense of sending people across interplanetary space?  With Mars the scientific stakes are arguably higher than they have ever been. The issue of whether life ever existed on the planet, and whether it persists to this day, has been highlighted by mounting evidence that the Red Planet once had abundant stable, liquid water and by the continuing controversy over suggestions that bacterial fossils rode to Earth on a meteorite from Mars. A more conclusive answer about life on Mars, past or present, would give researchers invaluable data about the range of conditions under which a planet can generate the complex chemistry that leads to life. If it could be established that life arose independently on Mars and Earth, the finding would provide the first concrete clues in one of the deepest mysteries in all of science: the prevalence of life in the universe.

单选题If there were life on Mars, such life forms()unable to survive on earthAisBareCwould beDwill be

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?

单选题Making water rapidly in all holds,all passengers and crew were ordered on deck()and all boats were lowered to rail.Ain life jacketsBwith life jacketsCwith life jackets onDputting on life jackets

单选题Last week a group of high school students were invited to the dinner party _____.Ato see the life style of the rich and politicalBto discuss international and public policy issuesCto learn to survive in different social situationsDto learn to become the future leaders of the White House

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.AwarmsBwarmedCwarmingDto warm

问答题Scientists hope that a remote lake on a dormant Chilean volcano can provide clues to what life may have been like in a far more distant place—the planet Mars.A 10-member team placed special plates in the lake on Licancabur volcano, at an altitude of 20,000 feet,on Sunday to measure the effects of ultraviolet light on organisms living there.The scientists, mostly from the United States, think learning how Licancabur organisms protect themselves may help researchers understand how life survived on early Earth and perhaps on early Mars as well.The damaging effects of UV radiation intensify at altitude and the air is very thin. And the lake is covered with ice most of the year, as would have been bodies of water on Mars.“If there was life on Mars 3.5 billion years ago, it could have used defense mechanisms similar to those used by the organisms at Licancabur volcano to survive,” said team leader Nathalie Cabrol.

单选题What does the underlined word “cheer” (Para. 1) imply?AImaginative men are sure of success in finding life on other planets.BImaginative men are delighted to find life on other planets.CImaginative men are happy to find a different kind of life existing on other planets.DImaginative men can be pleased with the idea that there might exist different forms of life on other planets.

单选题Many old people in the cities find themselves unable to get used to the rapid _____ of city life.ArateBspeedCstepDpace