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.

 

Hello, I’m Vladislav. For my summer holidays, I usually stay in a country house near Moscow.

Last summer, my dad’s brother gave me a present — a blue bike. At that time I couldn’t ride it very well.

One day I got into an accident. But don’t worry, everything was OK, just some “little” injuries.

That day, I tried to ride my bike and suddenly it began to move very fast. I couldn’t stop the bike. So I fell into a ditch (沟) full of dirty water. When I thought I had had enough bad luck, a girl walked by. She saw the bike and me. I quickly stood up.

“Are you fishing here?” she asked.

“Yes,” I answered. Then I said, “I’m making fish soup for dinner. Would you like to come?” To my surprise, she agreed.

After that we became friends. Now, we often send each other e-mails. She knows that I’m studying in China and she asks me questions about Chinese culture. I tell her my stories of China, and she says she wants to visit China, too. She even plans to study Chinese.

This is how, with the help of my bike, China got one more Russian friend.

根据短文内容,回答下列问题。

1.Who sent Vladislav a bike last summer?

                        

2.What happened when Vladislav tried to ride his bike?

                        

3. What did the girl think Vladislav was doing when she saw him by the ditch?

                        

4.What made Vladislav surprised?

                        

5. What does the girl say she wants to do in her e-mail to Vladislav?

                        

 

 0  31467  31475  31481  31485  31491  31493  31497  31503  31505  31511  31517  31521  31523  31527  31533  31535  31541  31545  31547  31551  31553  31557  31559  31561  31562  31563  31565  31566  31567  31569  31571  31575  31577  31581  31583  31587  31593  31595  31601  31605  31607  31611  31617  31623  31625  31631  31635  31637  31643  31647  31653  31661  159627 

违法和不良信息举报电话:027-86699610 举报邮箱:58377363@163.com

精英家教网