根据下面资料，回答题 Evolutionary theories. The Belgian George Lemaitre propose-考呗网题库移动版

单选题根据下面资料，回答题
Evolutionary theories. The Belgian George Lemaitre proposed the idea that about 20,000 million years ago all the matter in the universe--enough, he estimated, to make up a hundred thousand million galaxies-was all concen-trated in one small mass, which he called the " primeval atom". This primeval atom exploded for some reasons,
sending its matter out in all directions, and as the expansion slowed down, a steady state resulted, at which time the galaxies formed. Something then upset the balance and the universe started expanding again, and this is the state in which the universe is now. There are variations on this theory: it may be that there was no steady state. However,Basically, evolutionary theories take it that the universe was formed in one place at one point in time and has been expanding ever since.
Will the universe continue to expand? It may be that the universe will continue to expand for ever, But some astronomers believe that the expansion will slow down and finally stop. Thereafter the universe will start to contract until all the matter in it is once again concentrated at one point. Possibly the universe may oscillate for ever in this fashion, expanding to its maximum and then contracting over again.
The steady-state theory. Developed at Cambridge by Hoyle, Gold and Bodi, the steady-state theory maintains that the universe as a whole has always looked the same and always will. As the galaxies expand away from each other, new material is formed in some ways between the galaxies and makes up new galaxies to take place of those which have receded. Thus the general distribution of galaxies remains the same. How matter could be formed in this way is hard to see, But no harder than seeing why it should all form in one place at one time.
How can we decide which of these theories is closer to the truth? The method is in principle quite simple. Since the very distant galaxies are thousands of millions of light years away, then we are seeing them as they were thou-sands of millions of years ago. If the evolutionary theory is correct, the galaxies were closer together in the past than they are now, and so distant galaxies ought to appear to be closer together than nearer ones. According to the steady-state theory there should be no difference.
The evidence seems to suggest that there is a difference, that the galaxies were closer together than they are now, and so the evolutionary theory is partially confirmed and the steady-state theory--in its original form at least--must be rejected.
What do both theories assume to be true?

A．That new material is continually being formed.
B．That, in time, the universe will contract.
C．That the universe is expanding at present.
D．That "a big bang" started the expansion.

参考答案A

解析:短文赏析
本文探讨了关于宇宙形成的两种对立理论，一种是演化理论，一种是常态理论。演化理论认为宇宙中的所有物质原本集中于一个小团内，后来发生爆炸，散发出其物质，当爆炸慢下来时，便形成了稳态和星系。这种理论认为宇宙于一个时刻在一点形成，形成之后就不断膨胀。有些宇宙学家认为宇宙将膨胀到极点，再收缩到一点，再膨胀，不断轮回。而常态理论认为宇宙永远保持不变，将来也不会有任何变化，新物质形成代替旧物质，使宇宙保持永恒。观测证据支持了演化理论，驳斥了常态理论。
答案及解析
A【解析】由全文对两种理论对比看，B、c、D均不是两种理论共有的论点，只有A是。

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单选题According to Lemaitre, the separate galaxies formed _________.

A．during a pause in the expansion of the universe
B．at the time of the primeval explosion
C．and will continue to form for ever
D．when all the matter in the universe was all concentrated in one small mass

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单选题What is the basic difference betweon the two classes of theories?

A．It concerns the place and time of the formation of matter.
B．It is whether the universe will continue to expand or not.
C．It is the current state of the universe.
D．The variations on evolutionary theories cause the difference.

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单选题According to Hoyle and his friends at Cambridge, _________.

A．the explosion occurred much earlier than Lemaitre suggested
B．it is hard to see how matter could be formed in this way
C．the expansion of the universe is not a real one
D．new material is continually being created

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