题目内容
Astronomers estimate called the Pleiades in the constellation Taurus is 415 light?years away from Earth.
A.that a loose cluster of stars? B.a loose cluster of stars is ?
C.that is a loose cluster of stars? D.there is a loose cluster of stars
A
estimate是及物动词，后面的空格应该是宾语，或者宾语从句。A项从句的谓语是后面的is。B、C、D三项的谓语和后面的谓语矛盾了，一个句子只能有一个谓语。
The newly-discovered star was named ________ a Chinese astronomer ________ honor of his contributions to astronomy.
| A．for；in | B．after；for |
| C．as；in | D．after；in |
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."
【小题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 |
| 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 |
| 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 |
| 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. |