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
Bbpprzu大学英语四级新题型考试预测试卷4
interesting speculations as mathematical certainties.
注意：此部分试题请在答题卡2上作答。
62. 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
63. 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
64. 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
65. What is the author s attitude towards assumptions based on statistical evidence?
A) positive B) objective C) doubtful D) optimistic
66. 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
Part V Cloze (15 minutes)
Directions: There are 20 blanks in the following passage. For each blank there are four choices
marked A), B), C) and D) on the right side of the paper. You should choose the One that best fits into the passage. Then mark the corresponding letter on the Answer Sheet 2 with a single line through the center.
Today, most countries in the world have canals. Many countries have built canals near the
the coast. Even in the twentieth century, goods can be moved more cheaply ports along the coast without being to the dangers of the open. Some canals, such as the Suez and the Panama, save ships weeks of time by making their a thousand miles shorter. Other canals permit boats to reach cities that are not on the coast, still other canals lands where there is too much water, help to fields where there is not enough water, and water power for factories and mills. The size of a canal on the kind of boats going through it. The canal must be wide enough to permit two of the largest boats using it to the keel of the through a telescope, people saw that the round disk of the planet was criss-crossed by a of strange blue-green lines. These were called "canals" are viewed from an airplane. However, scientists are now that the Martian phenomena are really not
canals. The photographs "canals".
Bbpprzu大学英语四级新题型考试预测试卷4
注意：此部分试题请在答题卡2上作答。
67. A)off B)with C) to D) by
68. A) way B) means
69. A) possible B) difficult
70. A) among B ) between
71. A) revealed B) exposed
72. A) trip B) journey
73. A) lain B) stationed
74. A) escape B) drain
75. A) water B ) wet
76. A) furnish B) afford
77. A) focuses B) bases
78. A) cross B) pass
79. A) down B ) below C ) method D ) approach C) likely D) improbable C) in D) to C) opened D) shown C) voyage D) route C) set D) located C) dry D) leak C) soak D) irrigate C) offer D) give C) depends D) takes C) move D ) advance C) beneath D) off