4.（2011•江西卷）D

Why should mankind explore space? Why should money, time and effort be spent exploring and researching something with so few apparent benefits? Why should resources be spent on space rather than on conditions and people on Earth?

These are questions that, understandably, are very often asked.

Perhaps the best answer lies in our genetic makeup(基因构成) as human beings. What drove our ancestors to move from the trees into the plains, and on into all possible areas and environments? The wider the spread of a species, the better its chance of survival. Perhaps the best reason for exploring space is this genetic tendency to expand wherever possible.

Nearly every successful civilization has explored, because by doing so, any dangers in surrounding areas can be identified and prepared for. Without knowledge, we may be completely destroyed by the danger. With knowledge, we can lessen its effects.

Exploration also allows minerals and other potential (潜在的) resources to be found. Even if we have no immediate need of them, they will perhaps be useful later. Resources may be more than physical possessions. Knowledge or techniques have been acquired through exploration. The techniques may have medical applications which can improve the length or quality of our lives. We have already benefited from other spin-offs including improvements in earthquake prediction, in satellites for weather forecasting and in communications systems. Even non-stick pans and mirrored sunglasses are by-products (副产品) of technological developments in the space, the chance to save ourselves might not exist.

While many resources are spent on what seems a small return, the exploration of space allows creative, brave and intelligent members of our species to focus on what may serve to save us. While space may hold many wonders and explanations of how the universe was formed or how it works, it also holds dangers. The danger exists, but knowledge can help human being to survive. Without the ability to reach out across space, the chance to save ourselves might not exist.

While Earth is the only planet known to support life, surely the adaptive ability of humans would allow us to live on other planets. It is true that the lifestyle would be different, but human life and cultures have adapted in the past and surely could in the future.

71. Why does the author mention the questions in Paragraph1?
A. To express his doubts.
B. To compare different ideas.
C. To introduce points for discussion.
D. To describe the conditions on Earth.

72. What is the reason for exploring space based on Paragraph2?
A. Humans are nature-born to do so.
B. Humans have the tendency to fight.
C. Humans may find new sources of food.
D. Humans don’t like to stay in the same place.

73. The underlined word“spin-offs” in Paragraph 4 probably refers to______.
A. survival chances B. potential resources
C. unexpected benefits D. physical possessions

74. What makes it possible for humans to live on other planets?
A. O ur genetic makeup. B. Resources on the earth..
C. The adaptive ability of humans. D. By-products in space exploration.

75. Which of the statements can best sum un the passage?
A. Space exploration has created many wonders.
B. Space exploration provided the best value for money.
C. Space exploration may help us avoid potential problems on Earth.

解析：

71. 推理判断题。答案选C。文章是典型的议论说明文，是提出问题，分析问题的套路。第一段通过提出一系列关于太空探索利弊的问题引发讨论。并不是真的有这些怀疑，也没有鲜明的正反观点，所以AB不对。D偏差较远。

72. 主旨题。答案选A。第二段是典型的总分总结构，主旨句在段首段尾。Perhaps the best answer lies in our genetic makeup as human beings. 主要原因在于人类基因。Perhaps the best reason for exploring space is this genetic tendency to expand wherever possible. 而B选项错在fight这个词。CD没提及。

73. 词义猜测题。选C。根据spin off 前面的we have already benefited from other spin off 关键词 benefit，受益。而spin off后面的including … 说的全是获得的利益，如improvements in earthquake prediction. 地震预测的进步等等，而不是什么生存机会，或者潜在资源。所以选C。

74. 细节题。答案选C。按照问题顺序一致原则，答案应当出现在最后两段。在最后一段的首句我们找到了一个极端词用以定位。While earth is the only planet known to support life, surely the adaptive ability of humans would allow us to live on other planets.直接由翻译可知，人类的适应能力使我们在其他星球的居住成为可能。

75. 推理判断题。选D。除去前两段引入，第三段主旨句（首句）的意思是每个文明都会探索周围文明以减低危险，第四段主旨句（首句）说的是探索使得我们能够发现潜在能源。第五段主旨句（首句）说的是探索使得很多人发现解决问题的有用资源。总的来说，就可归结为，太空探索可以帮助我们很多，避免很多问题。