2014年英语四级考试模拟试题及答案(第四套)_第5页

　　Questions 26 to30 are based on the following passage.

　　In a recent article, mathematician Aczel argues convincingly that the number of planets suitable for life is extremely large. There are about 300 billion stars in our galaxy (银河系 ) and possibly 100 billion galaxies in the universe. Some may quarrel with Aczel’ s claim that as many as half of these stars can be presumed to have planets, and that on average one in nine of those planets is suitable for life; but few, I think, will disagree with his conclusion that there are a very large number of planets suitable for life.

　　The trouble starts when we come to estimate the probability that life will emerge on any of these planets. The problem is that we don’ t have a good theory of the origin of life on earth. Without one, it is anybody’ s guess how likely this event actually was. Out of thin air Aczel conjures the figure of 1 in a trillion for this likelihood and concludes that the probability of life existing on at least one other planet is virtually 1.

　　Statistics are extremely powerful and important, and Aczel is a very clear and capable exponent (倡导者) of them. But statistics cannot substitute for empirical (经验主义的) knowledge about the way the universe behaves. We now have no reasonable way of arriving at robust estimates for the probability of life arising spontaneously when the conditions are right. So, until we either discover extraterrestrial (外星球的 ) life or understand far more about how at least one form of life----terrestrial life----first appeared, we can do little more than guess at the likelihood that life exists elsewhere in the universe. And as long as we’ re merely guessing, we should not dress up our interesting speculations as mathematical certainties.

　　注意：此部分试题请在答题卡2上作答。

　　26. The term "Out of thin air" in Line 3 of Paragraph 2 can be best replaced by__________.

　　A) convincingly B) confidently C) groundlessly D) suitably

　　27. According to the passage, what we can do about the likelihood of extraterrestrial life is to _____.

　　A) find a good way of reaching a conclusion

　　B) construct a good theory of the origin of life

　　C) replace statistics with empirical knowledge

　　D) find whether the conditions for life are right

　　27. Though challenged by many people, Aczel firmly believes that ______.

　　A) about 1 million planets in our galaxy are suitable for life

　　B) it is very likely for life to exist on other planets

　　C) life exists in approximately 150 billion stars in our galaxy

　　D) there are a very large number of planets suitable for life

　　29. What is the author’s attitude towards assumptions based on statistical evidence?

　　A) positive B) objective C) doubtful D) optimistic

　　30. The author’ s purpose in writing this article is to _______.

　　A) tell the reader not to rely only on statistics when dealing with the universe

　　B) encourage the reader to do some researches about the extraterrestrial life

　　C) tell the reader something about possible extraterrestrial life on other planets

　　D) show his interest in Aczel’ s research in extraterrestrial life on other planets