Of all the problems facing modern astronomers, perhaps the most fascinating is "Can intelligent life exist elsewhere?" Since the earth is an unimportant planet moving round an unimportant star, it would be a pride on our part to suppose that we are the only intelligent beings in the universe. But to obtain proof is difficult.

The main trouble is that our neighbour worlds, the bodies in the Solar System appear to be unsuitable for advanced life-forms. The Moon may be ruled out at once;it has hardly any atmosphere. Venus is little better;the surface temperature is extremely high and the atmosphere is mostly carbon dioxide. Mars with a very thin atmosphere and a severe shortage of water, may well support simple plant life but there seems be no hope of finding animals, while the attractive Martians of the story-tellers have long since been given up.

Of course this has not stopped the flow of bright ideas for communicating with the supposed people on Mars. In the early nineteenth century the great mathematician Gauss suggested planting tree-patterns in Siberia, that the Martians would see them and reply suitably. Following up this idea, the Austrian scientist Karl Littmw proposed digging very wide ditches In the sahara, triangular（三角形的）in pattern, and then filling them with petrol or some such substance so that, when lit,the ditches would present Martian observers with a “flaming triangle” which would show the existence here of intelligent minds. Even better were the plants of Charles Cros, a French writer of the 1870's, who wanted to build a large mirror to reflect the sun's rays and concentrate them on the surface of Mars, thereby making a vast, burning-glass. By swinging the mirror around, Gros explained it would be practicable to write words in the Martian deserts simply by burning the sand. For many years he bombarded（连续质问的）the French government with literature about this plan and was very disappointed when no official interest was shown.

1. The opinion of the writer is that ________.

A. there may be other intelligent beings in the universe

B. there are other intelligent beings in the universe

C. people living on the earth are almost certainly the only intelligent beings in the universe

D. people living on the earth are definitely the only intelligent beings in the universe

Best Answer:A

详解：答案A。题目要求读懂作者的观点。第一段更后两句指出，由于地球是一颗围绕一颗不重要的恒星转动的行星，因而我们可以自豪地假定我们是宇宙中唯一的智能生命。但是要证实这种假设很难。可见，我们是宇宙中唯一存在的智能生命这种假定没有确凿的依据。换句话说，宇宙中可能存在其他的智能生命。A项说法正确。B、C、D三项说法均未肯定，故不对。

2.There is unlikely any life on Venus because ________.

A. the surface temperature is too hot

B. the weather is too cold

C. it is severely short of water

D. it has a very thin atmosphere

Best Answer:A

详解：答案A。第二段第三句指出了金星不存在生命的原因:表现温度过高，并且大气主要是由二氧化碳组成。A项说法与之相符；B项与此相反，故不对;C、D两项不是金星上不存在生命的原因，也不对。

3.It seems that Mars ______.

A. may be inhabited by attractive Martians

B. may have some vegetable life

C. can have no life at all

D. may have both vegetable and animal life

Best Answer:B

详解：答案B。从第二段更后一句中的may well support simple plant life but there seems no hope of finding animals可知，火星上可能有植物生命，但没有动物，然而火星人存在的说法也被放弃了。B项说法正确，A、C、D三项不对。

4.Gauss wanted to establish contact with the Martians by______.

A. planting trees in triangular shape

B. filling wide ditches with oil

C. building a large minor

D. making patterns with trees

Best Answer:D

详解：答案D。题目问及Gauss想通过何种方式与火星人建立联系。第三段第二句指出19世纪早期，伟大的数学Gauss 建议在西伯利亚种树，以便火星人看见并适当地作出反应。B、C两项与此不符。A项为干扰项，文章并没有说以三角模式来种树，故A项不对。D项说法与此一致，因此D项为正确答案。

5.Charles Cros felt ______.

A. angry when the government paid little attention to his ideas

B. pleased when the government did take notice .of his plan

C. surprised that the officials were interested in his suggestion

D. disappointed at the lack of interest shown in his plan Passage Three

Best Answer:D

详解：答案D。从第三段更后一句可知Charles Cros的态度是感到很失望，因为政府无人对他的计划感兴趣。因此D项为正确答案。