Question

Still waiting for little green men to make contact? Don't hold your breath.

A leading astronomer has concluded there probably aren't any aliens out there – meaning we are absolutely alone in the universe.

Even though there may be tens of thousands of other distant planets similar in size to Earth, the conditions on them are likely to be too hard to support life-forms such as ET.

Dr Howard Smith, a senior astrophysicist at Harvard University, believes there is very little hope of discovering aliens and, even if we did, it would be almost impossible to make contact.

So far astronomers have discovered a total of 500 planets in distant solar systems – known as extrasolar systems – although they believe billions of others exist.

But Dr Smith points out that many of these planets are either too close to the sun or too far away, meaning their surface temperatures are so bad that they could not support life. Others have unusual orbits which cause vast temperature variations, making it impossible for water to exist – the most important thing for life.

Dr Smith said, "We have found that most other planets and solar systems are wildly different from our own. It means it is highly unlikely there are any planets with intelligent life close enough for us to make contact." But his suggestions contradict other leading scientists who have claimed aliens almost certainly exist.

Only last month Professor Stephen Hawking said the fact that there are billions of galaxies out there made it reasonable to think there were other life-forms in the universe.

Researchers from the University of London have recently suggested that aliens could be living on as many as 40,000 other planets. But Dr Smith said: "Any hope of contact has to be limited to a relatively tiny space around the Earth, reaching maybe 1,250 light years out from our planet, where aliens might be able to pick up our signals or send us their own. But communicating would still take decades or centuries."

1.By saying ＂don’t hold your breath＂, the author advised the reader not to _____.

A．keep silent        B．give up           C．expect so         D．be afraid

2.Dr Smith concludes there probably aren’t any aliens because other planets _____.

A．are too far away from the earth

B．are different from the Earth in size

C．don’t have rich natural resources

D．don’t have a suitable living environment

3.Researchers from the University of London are mentioned to show that ______.

A．they have better explanations about aliens

B．aliens certainly exist on many planets

C．they disagree with Dr Smith’s suggestion

D．aliens can pick up signals from the earth

4.What’s the main idea of the text?

A．There must be other life forms in the universe.

B．We can communicate with aliens in decades.

C．The chances of finding aliens are slight.

D．Many other planets are quite different from the Earth.

Answer

1.C

2.D

3.C

4.C

【解析】

试题分析：文章讲述了天文学家对外星人是否存在的事实进行论述，要想找到外星人的几率是非常小的，几乎可以说我们是太空唯一的生物群。

1.推断题。从后文A leading astronomer has concluded there probably aren't any aliens out there – meaning we are absolutely alone in the universe.可知科学家已经得出不可能有外星人的存在，我们是宇宙中唯一的生物，故选C

2.细节题。从文章the conditions on them are likely to be too hard to support life-forms such as ET.可知，由于生存条件的恶劣，不可能有像外星人这样的生物存在，故选D

3.细节题。从文章Researchers from the University of London have recently suggested that aliens could be living on as many as 40,000 other planets.可知他们认为有外星人的存在而Dr Smith并不认为这样，故选C

4.主旨题。从全文及最后一段reaching maybe 1,250 light years out from our planet, where aliens might be able to pick up our signals or send us their own. But communicating would still take decades or centuries."可知，要想找到外星人的几率几乎是微乎其微，故选C

考点：科普类说明文