For centuries, explorers have risked their lives venturing into the unknown for reasons that were to varying degrees economic an

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问题     For centuries, explorers have risked their lives venturing into the unknown for reasons that were to varying degrees economic and nationalistic (国家主义的). 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 Appolo 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 simply by going where no scientists had gone before.
    Today Mars looms (隐约出现) as humanity’s next great terra incognita (未探明之地). And with growing emphasis on international cooperation in large space ventures, it is clear that imperatives (需要, 必要) 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 experiments that only humans 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 (陨石) 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.
The passage tells us that proof of life on Mars would______.

选项 A、make clear the complex chemistry in the development of life
B、confirm the suggestion that bacterial fossils traveled to Earth on a meteorite
C、reveal the kind of conditions under which life originates
D、provide an explanation why life is common in the universe

答案C

解析 细节题。最后一段倒数第二句话说:对火星上过去或现在是否存在生命给出一个更确凿的、令人信服的回答,会给研究者提供产生生命条件的宝贵数据。这与C项的表述一致。而只有进一步证明生命在火星上不仅仅存在而且是独立产生的,才能进~步解释“生命在宇宙中是否普遍存在”这个谜,所以不能选D项。
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