阅读下面短文，把方框中的句子还原到文中，然后完成第五小题。（每题1分，共5 分）If you look at the sky one night and see something

阅读下面短文，把方框中的句子还原到文中，然后完成第五小题。（每题1分，共5 分）
If you look at the sky one night and see something moving and shining that you have never seen before, it might be a comet (彗星).
　　A comet sometimes looks like a star. 【小题1】 It shines from the sunlight it reflects (反射). Like the earth, a comet goes round the sun, but on a much longer path (轨道) than the earth travels.
If a comet isn’t a star, what is it then?
　 Some scientists think that a large part of a comet is water frozen into pieces of ice and mixed with iron and rock dust and perhaps a few big pieces of rock. 【小题2】 These clouds, together with the dust, form a long tail.
Many people perhaps have seen a comet. 【小题3】 .There may be millions of comets, but only a few come close enough for us to see.
An Englishman named Edmund Halley, who lived from 1656 to 1742, found out a lot about the paths that comets take through the sky. 【小题4】 . Others keep coming back at regular times. A big comet that keeps coming back was named after Halley because he was the one who worked out when it would come back again. Maybe you have ever seen Halley’s Comets because the last time it came close to the sun and the earth was in the year 1986. Then people all over the world were outside at night to look at it. You will probably be able to see Halley’s Comets when it comes near the earth again.
A. However no one knows how many comets there are.
B. Some comets move out of our sight and never come
C. Like a planet, a comet has no light of its own.
D. When sunshine melts (融化) the ice in the comet, great clouds of gas go trailing after it.
【小题5】Which of the following is not true?A．A large part of a comet is ice, iron and rock dust B．Some comets keep coming back at any time C．Halley’s Comets came back in 1986D．Maybe many people have seen a cometC

(答案→)C 解析：这篇短文主要介绍了彗星的组成部分，为什么叫做彗星。彗星有一部分会移出我们的视线再也不回来，但又有一部分会定期回来像哈雷彗星。【小题1】根据后文It shines from the sunlight it reflects (反射)可知彗星像行星一样本身不发光。故选C。.【小题2】根据后文These clouds, together with the dust, form a long tail.可知这些云加上尘埃形成长长的尾巴。可知上文会提到云的形成故选D。【小题3】上文许多人可能见过彗星。根据句子的转折词.However，可知与上文发生转折。故选B。【小题4】根据后文Others keep coming back at regular times. 其他的彗星会定期回归可知前文再说一些彗星。故选B。【小题5】是非判断题。根据Others keep coming back at regular times.可知彗星会定期回归。故B项是错误的。

我明天再问问老师，叫他解释下这个问题