Since people first launched rockets into space in the 1950s, we have been leaving behind all sorts of things. Some of them, like the camera, were lost by astronauts while they did work outside their spacecraft. But 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.

Some things we send into space fall back toward Earth and burn up in the atmosphere. But larger pieces sometimes survive the extreme heat and hit the ground or the ocean at great speeds. So there is always concern that something may fall from the sky and do some harm.

But space junk falling on roofs is not the biggest worry. Scientists are concerned about the “Kessler” problem. 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, says 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. Mr.Castronuovo has proposed using a number of small satellites with robotic arms. One arm would catch the space junk, and another arm would connect the rocket. He imagines that each satellite could jump from one large piece of junk to another. He thinks this method could destroy about ten large objects each year.

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. So what can be done to clean up the space around our planet?

1.We can learn from the text that much of the space junk ________.

A. was left by the astronauts on purpose

B. is mainly made up of broken spaceship

C. is usually made of small pieces of things

D. burns up before it reaches the atmosphere

2.Now scientists are most worried that space junk will ________.

A. harm the future space vehicles

B. do some harm to the atmosphere

C. fall on people's house roofs

D. destroy the habitat of wildlife

3.It implies in the last but one paragraph that ________.

A. clearing up the space will actually cost little

B. small rockets also do harm to the atmosphere

C. only robots can clear up the space completely

D. it is still difficult for us to clear up the space

4.What is the text mainly about?

A. Space junk threatens earth's orbital environment.

B. Scientists use different methods to clear up space junk.

C. Spacecrafts will meet with a lot of space junk in the future.

D. Marco comes up with many methods to deal with space junk.

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刪除：把多余的詞用斜線（＼）劃掉。

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When my father bought me a computer as a birthday gift in last year,I felt very exciting.As we all know, computers are getting more and more usefully now.Much informations can be stored in them.We can also learn that has lately happened in the world on Internet.In the past,people had to do lots of work which was very dangerous. Now,but,computers can do it instead.When an exam is coming,I often did some exercises on my computer.Then it will correct it and tell me the right answers.In this way it is more convenient for me to preparing for exams than before.The computer has become my real friend.

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Autumn is a time when nature prepares to test and it is just the same with many people.With less energy or strength they have no desire to meet with friends after work，preferring to sit still in front of the television before going to bed early.And the next morning they find it hard to get up, too.

For most people, this period of time passes without any major effects, but a small minority suffer from complete winter depression(壓抑)．Apart from tiredness and without energy, the latter often has the following symptoms(癥狀)．

They have an increased need for sleep and also for sweet food like chocolate.Normally, depression is along with difficulty in falling asleep and loss of appetite(胃口)．

True winter depression exists when the symptoms occur repeatedly in autumn and winter.Moreover, they have to last at least two weeks.Symptoms of winter depression begin for northern hemisphere(北半球)countries in October, November or December, and reduce in January.The symptoms decrease when the days grow longer again.

Lack of light during the cold months is the cause of people's depression.

To reduce the bad effect of the winter depression, sufferers should spend as much time outdoors as possible.Exercise is also a tested cure for depression.A regular sleep wake cycle can help too, and sufferers should stick to it even at weekends.By getting up early, they can receive more daylight regardless of the weather.

Title

Light up your life

Main idea

People who 1. from winter depression can light up their life.

2.

·Feel tired.

·Lack 3..

·Need more sleep and sweet food.

·Find it 4. to go to sleep.

·Have no 5. to have meals.

Occurrence

·Winter depression exists with the symptoms occurring over and over again in autumn and winter, and

6. two weeks or longer.

·Winter depression starts for northern hemisphere countries in October, November or December and 7. in January.

Cause

·8. to lack of light in cold weather

Solutions

·Spend as much time outdoors as 9..

·Take exercise.

·Go to bed and get up

10. every day.

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