When you look up into the sky at night, have you ever felt that your eyes are playing tricks on (捉弄) you? It seems that the stars are moving all the time.

Actually, there is nothing wrong with your eyes. This twinkling effect is called scintillation (交光). Scintillation happens because of air movements in the earth’s atmosphere (大气). Light is “bent (弯曲的)” when it travels through different parts of the earth’s atmosphere. As the air in the earth’s atmosphere is moving all the time, the light from the stars looks as if it is moving too.

The same thing also happens to things on the ground. On a very hot and shiny day, if you look at the road, the image in the distance is not clear and things move slightly. You can also see the same effect if you drop a rock into water. The rock appears a little unclear under the moving water.

This twinkling effect causes a lot of problems for astronomers (天文学家) since they cannot observe the stars clearly. A telescope (望远镜) was sent into space so that the air movements in the atmosphere could be avoided (避免). It took a long time to build the space telescope but finally in 1990, a huge space telescope called the Hubble Space Telescope was successfully sent into space. Since then, astronomers have many important observations that have helped people understand space better.

根据短文内容，选择最佳选项。 （10分）

1.What happens to the light from the stars we see when the air in the earth’s atmosphere is moving?

A．It looks even brighter.

B．It looks as if it is bent.

C．It looks as if it is moving.

D．It looks like drops of rain.

2.Scintillation also happens on 　　　　 according to the passage.

A．rainy days                             B．shiny days

C．cloudy days                            D．windy days

3.What can you see when you drop a rock into the water?

A．The rock gets broken.

B．The rock becomes unclear.

C．The water becomes much polluted.

D．The water does not move anymore.

4.The underlined word “observe” means “　　　　”.

A．watch            B．listen             C．draw             D．explain

5.Why is scintillation a problem for astronomers?

A．The stars never stay still.

B．It makes the stars too dark to see.

C．It makes astronomers feel too hot to work.

D．Astronomers cannot observe the stars clearly.

阅读短文，根据短文内容，从短文后的六个选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。（共8分，每小题2分）

　　As you grow rapidly through your teenage years, you will experience a lot of changes. The changes may seem difficult. 　1　 　Don’t panic! You will deal successfully with them! You are a young adult now!

　　With more responsibility, you will find more freedom to make your own choices. This is a time to be well informed about making choices. In this way you can make healthy balanced decisions. 　2　 　You may already know your career path or you may have no idea at all what you want to do. Both situations are fine! Work hard and the right opportunity will present itself to you.

　　Young adulthood means greater freedom and more choices. 　3　 　But try not to shut your family out of your life. You should learn to think of others even though you are old enough to look after yourself.

　　It is also perfectly natural at this time for you to spend more time with your friends than your family. Choose your friends wisely. A true friend will stand by you no matter what happens.

　　This period is a part of the life cycle. There are some people who will be with you throughout life’s journey. There will be some people with whom you part and go separate ways. Leaving school can be hard. The reality is that you may not even see all of your classmates again.

　　You are a young adult. It is your life. No one can live it for you. 　4　 　So making the right choices will be important to you. Life is for living. Enjoy your life wisely.

　　A. They will help shape the future.

　　B. They may seem to happen quickly.

　　C. You will probably want to be independent.

　　D. You may appreciate what you have in your own life.

　　E. The choices that you make from now on will be your choices.

　　F. Your family has been with you since you came into this world.

短文填空 (共10分，每空1分)

完形填空（15分）
阅读下面短文, 掌握其大意，然后从各题所给的A、B、C、D四个选项中，选出最佳选项。
I stood in the doorway, watching my elder brother carefully putting clothes into his bag. I coughed uneasily. Finally 　　36　　 that I was there, Rocky turned towards me with a sad smile.
“I’m 　　37　　 tomorrow,” he said.
“I know.” My __38____ was almost a whisper. I was 　　39　　 at myself for being so weak, but I wasn’t about to cry.
“My 　　40　　 is early, so there is still 　　41　　 time to come to the airport,” he said. Seeing the 　　42　　 look on my face, he quickly added, “I promise I won’t leave without saying goodbye.”
I tried to say 　　43　　 , but didn’t. It’s always 　　44　　 to keep quiet if you’re about to cry. “You promised you wouldn’t cry,” he said to me, thinking that I was close to 　　45　　.
I remember the day he taught me how to ride a bike. 　　46　　 I thought he was always right behind me, holding the seat to keep me from 　　47　　. I was happy with this, but he knew he couldn’t hold me up all my life. He told me that one day he would have to let go.
His coughing stopped my thinking. What was left to say? How could I say 　　48　　 to the person who taught me everything?
The next morning I 　　49　　 , looked at my alarm clock, and realized he had left　50　 ago. We never even said goodbye.
Goodbye, Rocky! Although he may have been many miles away, I knew he heard me, even if it was only an answer in his heart.