7. Sandstorms a major disaster for many Asian countries for centuries.

   A. were        B. are

   C. have been   D. will be

6. It was the most and the most dangerous situ- ation Fve ever been in.

   A. frighten   B. frightening

   C. frightened   D. being frightening

5. So if you want to go out,you’d better a mask.

   A. to wear   B. wearing

   C. wear   D. wore

4. A mass has been started to help solve it.

   A. campaign   B. war

   C. battle   D. fight

3. When a sandstorm arrives in the city,weather experts people not to go out.

   A. hope   B. let

   C. make   D. advise

2. Scientists have tried many ways this prob- lem.

   A. solve        B. to solve

   C. of solving   D. both B and C

1. This is a that happens when land becomes desert.

   A. process   B. produce

   C. procedure   D. pronunciation

5. To prevent it coming nearer,the government is planting trees.

翻译：

仿写:为了健康，他天天早起跑步。

4. The storms sometimes continue all day and traffic moves very slowly because the thick dust makes it difficult to see.

翻译.

仿写她的解释使我们对课文的理解变得容易起来。

3. Sandstorms in China appear to have increased in recent years as a result of “desertification”.

翻译

仿写他好像知道此事了。