题目内容
If you look into the sky at night, you may 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.
Some scientists think that a large part of a comet is water frozen into pieces of ice. This is mixed with iron and rock dust and perhaps a few big pieces of rock. When the sun melts(融化) the ice in the comet, great clouds, together with the dust, form a long tail. Many people 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 to the earth for us to be able to see them. Even then it’s not often that a comet comes close enough to be seen without a telescope.(望远镜).
An English man named Edmund Halley, who lived from 1656 to 1742, found out a lot about the paths that comets take through the sky. Some comets never come back. Others keep coming back at regular intervals(有规律的间隔). A big comet that keeps returning was named after Halley because he was the one who worked out when it would come back again.
Some people saw Halley’s Comet in 1910. Maybe you have ever seen Halley’s Comet because the last time it came close to the sun and the earth was in 1986. If not you will probably be able to see Halley’s Comet when it comes near the earth again.
( )31.Which of the following statements is correct?
A. So far, no one has ever seen a comet. B. A comet can shine by itself.
B. A comet travels around the sun. D. A comet is either a star or a planet.
( )32. A large part of a comet is .
A. water frozen into pieces of ice B. ice and iron
C. rock dust and a few big pieces of rock D. ice, iron and rock dust
( )33. Which of the following statements is incorrect?
A. Not many comets can be seen by people B. Edmund Halley discovered all the paths that comets take through the sky C. Halley died in the 18th century. D. Halley’s Comet will return
( )34. Some comets return .
A. at regular intervals B. only at night C. at my home D. at noon
( )35. Maybe you will be able to see Halley’s Comet in .
A. 2003 B. 2056 C. 2062 D. 2072
31—35 CABAC