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Since the first satellite was launched in 1957, humans have sent thousands of objects into space. Many of them are still there, but some are no longer working. These old satellites, rocket parts, and other pieces of metal are called space junk. They orbit Earth at high speeds and can be very dangerous.
Space junk can hit working satellites and destroy them. It can also threaten astronauts on the International Space Station. Even a small piece, the size of a pea, can cause serious damage because it moves so fast. Scientists estimate（估计）that there are over 500,000 pieces of space junk larger than a marble. Some are big enough to see with the naked（裸露的）eye, but most are too small.
What can we do about space junk? One idea is to collect it with special robots. Another is to make sure new satellites are designed to fall back to Earth and burn up after they finish their work. Some countries are working together to find solutions. However, we cannot afford to wait too long. The average amount of space junk is increasing every year. If we don’t act soon, it might become impossible to launch new satellites.
Space agencies are also trying to track space junk. They use radar and telescopes to watch where it goes. When a probable collision（碰撞）is predicted, they can move satellites out of the way. This happened to the International Space Station several times. So next time you look up at the night sky, remember that there’s more up there than just stars.
29. What is space junk?
A. Fuel left by rockets.
B. Stars that have fallen to Earth.
C. New satellites that are working.
D. Old, non-working objects in space.
30. Why is space junk dangerous?
A. It uses up all the fuel.
B. It blocks our view of the stars.
C. It can slow down working satellites.
D. It can hit and destroy working satellites.
Unit Six
31. How can scientists predict possible collisions?
A. By using radar and telescopes.
B. By looking with the naked eye.
C. By designing satellites to fall back.
D. By sending astronauts to collect junk.
C
Space junk can hit working satellites and destroy them. It can also threaten astronauts on the International Space Station. Even a small piece, the size of a pea, can cause serious damage because it moves so fast. Scientists estimate（估计）that there are over 500,000 pieces of space junk larger than a marble. Some are big enough to see with the naked（裸露的）eye, but most are too small.
What can we do about space junk? One idea is to collect it with special robots. Another is to make sure new satellites are designed to fall back to Earth and burn up after they finish their work. Some countries are working together to find solutions. However, we cannot afford to wait too long. The average amount of space junk is increasing every year. If we don’t act soon, it might become impossible to launch new satellites.
Space agencies are also trying to track space junk. They use radar and telescopes to watch where it goes. When a probable collision（碰撞）is predicted, they can move satellites out of the way. This happened to the International Space Station several times. So next time you look up at the night sky, remember that there’s more up there than just stars.
29. What is space junk?
A. Fuel left by rockets.
B. Stars that have fallen to Earth.
C. New satellites that are working.
D. Old, non-working objects in space.
30. Why is space junk dangerous?
A. It uses up all the fuel.
B. It blocks our view of the stars.
C. It can slow down working satellites.
D. It can hit and destroy working satellites.
Unit Six
31. How can scientists predict possible collisions?
A. By using radar and telescopes.
B. By looking with the naked eye.
C. By designing satellites to fall back.
D. By sending astronauts to collect junk.
C
答案
29. D
30. D
31. A
30. D
31. A
解析
【分析】
本题为英语阅读理解细节题，需根据题干关键词定位原文对应段落，提取关键信息作答。29题关键词“space junk”定位第一段找定义；30题关键词“dangerous”定位第二段找危险原因；31题关键词“predict possible collisions”定位第四段找预测方法。
【解析】
29题：根据文章第一段“These old satellites, rocket parts, and other pieces of metal are called space junk.”可知，太空垃圾是太空中旧的、不工作的物体，A选项火箭剩余燃料、B选项落到地球的星星、C选项工作的新卫星均不符合，故选D；
30题：根据文章第二段“Space junk can hit working satellites and destroy them.”可知，太空垃圾的危险在于能撞击并摧毁工作中的卫星，A选项耗尽燃料、B选项遮挡星星、C选项减慢卫星速度均未提及，故选D；
31题：根据文章第四段“They use radar and telescopes to watch where it goes. When a probable collision is predicted...”可知，科学家通过雷达和望远镜预测可能的碰撞，B选项肉眼看、C选项设计卫星返回、D选项送宇航员收集垃圾均不符合，故选A。
【答案】
29.D；30.D；31.A
【知识点】
英语阅读理解（细节理解）
【点评】
本题为英语阅读理解细节题，侧重考查学生快速定位原文信息的能力，难度较低，仔细阅读原文对应段落即可找到答案。
【难度系数】
0.8
本题为英语阅读理解细节题，需根据题干关键词定位原文对应段落，提取关键信息作答。29题关键词“space junk”定位第一段找定义；30题关键词“dangerous”定位第二段找危险原因；31题关键词“predict possible collisions”定位第四段找预测方法。
【解析】
29题：根据文章第一段“These old satellites, rocket parts, and other pieces of metal are called space junk.”可知，太空垃圾是太空中旧的、不工作的物体，A选项火箭剩余燃料、B选项落到地球的星星、C选项工作的新卫星均不符合，故选D；
30题：根据文章第二段“Space junk can hit working satellites and destroy them.”可知，太空垃圾的危险在于能撞击并摧毁工作中的卫星，A选项耗尽燃料、B选项遮挡星星、C选项减慢卫星速度均未提及，故选D；
31题：根据文章第四段“They use radar and telescopes to watch where it goes. When a probable collision is predicted...”可知，科学家通过雷达和望远镜预测可能的碰撞，B选项肉眼看、C选项设计卫星返回、D选项送宇航员收集垃圾均不符合，故选A。
【答案】
29.D；30.D；31.A
【知识点】
英语阅读理解（细节理解）
【点评】
本题为英语阅读理解细节题，侧重考查学生快速定位原文信息的能力，难度较低，仔细阅读原文对应段落即可找到答案。
【难度系数】
0.8
