Question

阅读理解 　　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．Like a planet, a comet has no light of its own．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．When sunshine melts(融化)the ice in the comet, great clouds of gas go trailing after it．These clouds, together with the dust, form a long tail． 　　Many people perhaps have seen a comet．However no one knows how many comets there are．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．Some comets move out of our sight and never come back．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． (1) A comet is like ________． [　　] A． sun B． moon C． sunlight D． the earth (2) A large part of a comet is ________． [　　] A． water and rock B． water frozen into pieces of ice and mixed with iron C． ice, iron and rock dust D． only a few big pieces of rock (3) Maybe many people ________． [　　] A． haven’t seen any comets B． have seen all comets C． have seen a comet at daytime D． have seen a comet (4) Some comets keep coming back ________． [　　] A． at any time B． at noon C． at regular times D． at daytime (5) Halley’s Comets came back ________． [　　] A． in 1990 B． in 1980 C． in 1986 D． in 1989

Answer 1

答案：1．D;2．C;3．D;4．C;5．C;
解析：

(1)	“Like the earth, a comet goes round the sun, but…”是判断本题的根据．
(2)	根据“…is water frozen into pieces of ice and mixed with iron and rock dust and perhaps a few big pieces of rock．”这句话即能得出答案．
(3)	由第五段的首句“Many people perhaps have seen a comet．”可知．
(4)	“Some comets move out of our sight and never come back．Others keep coming back at regular times．”一句是答案的出处．
(5)	哈雷彗星每七十六年才能看到一次．再结合“…the last time it came close to the sun and the earth was in the year 1986．”这句话的意思，即可得到答案． 　　本文向我们介绍了有关彗星方面的知识．与地球一样，彗星也是绕太阳旋转的，它本身不发光，靠反射太阳的光而发亮．短文中还介绍了彗星的成因，它拖着的长尾巴是如何形成的以及著名的哈雷彗星名字的由来．