Question

A camera, a glove, a hand tool, even a toothbrush… they are all up there, above the clouds, going around and around the Earth. There are also thousands of pieces of metal and plastic. Some of them are only about the size of a fingernail. Many are much larger. Scientists consider all these objects to be space junk, and they are a problem.

　　　 Since people first launched rockets into space in the 1950s, we have been leaving behind all sorts of things. Much of the space junk is made up of little pieces of things that were once bigger objects, until they struck each other and broke apart. Sometimes larger pieces survive the extreme heat through the atmosphere and hit the ground or the ocean at great speeds.

　　　 But space junk falling on housetops is not the biggest worry. Scientists are concerned about the Kessler syndrome. It is named after the American scientist who first thought of the idea in 1978. Imagine what happens when an empty rocket strikes another while orbiting the Earth. Two big things become many smaller things. They then hit other things. The pieces get smaller and smaller until they form a cloud of junk that blocks the path of future space vehicles.

　　　 Marco Castronuovo, an Italian Space Agency researcher, suggested launching a satellite into space that would get very close to some of the larger pieces of space junk. The satellite would connect a small rocket to the useless object. When the rocket explodes, it pushes the junk into a lower and slower orbit, nearer the Earth. After a time, the junk burns up in the atmosphere.

　　　 Scientists have been concerned about space junk for many years. Right now, the costs of the clean- up have been too great. Mr. Castronuovo says his system could be put in place for a much more reasonable amount of money.

67.　 What does the underlined part “space junk” in Paragraph 1 refer to?

A.It refers to small pieces of things that were once bigger objects.

B.It refers to objects that survived the extreme heat through the atmosphere.

C.It refers to clouds that are made up of small objects in space.

D.It refers to all kinds of objects that have been left behind in space.

68.Why do scientists consider the Kessler syndrome a big problem?

A.Space junk clouds are likely to block the path of spacecraft.

B.An empty rocket might strike a spacecraft orbiting the Earth.

C.Space junk might fall onto the Earth, causing damage.

D.Space junk becomes bigger and bigger until hard to get rid of.

69.What is mainly talked about in the passage?

A.Smaller objects come together to form clouds of space junk.

B.Human beings are responsible for space junk.

C.Space junk is a big problem human beings have to find ways to solve.

D.An Italian researcher has found a good way to remove space junk.

70.What is the author’s attitude towards Marco Castronuovo’s method of cleaning up space junk?

A.　 Doubtful. 　　　　　　 B.　 Objective.　　　　　　 C.　 Favorable.　　 D.　 Disapproving.

Answer 1

DACB