阅读理解。

     Mr. Green comes from U.S.A. He works in Beijing. He teaches English in a middle school. And he

studies Chinese in an evening school. He can read and write a little Chinese now. He has many Chinese

friends in Beijing. They are very friendly.

     He has two children. One is a girl, and the other is a boy. They study in Beijing but they are in

different grades. Their mother is an English teacher, too. They all like China. They like Chinese food

very much.

1. Mr. Green is _____. But he works in _____.

A. teacher; U.S.A.  

B. American; China  

C. America; Beijing  

D. teacher; China

2. He _____ English in a middle school and _____ Chinese in Beijing.

A. teaches; learns  

B. learns; teaches  

C. learns; learns  

D. teaches; teaches

3. He can write _____ now.

A. no Chinese  

B. a little Chinese  

C. Chinese very well  

D. good Chinese

4. His children _____ students in a middle school in _____.

A. are; Beijing  

B. aren't; China  

C. are; U.S.A.  

D. aren't; Beijing

5. His wife teaches English in _____, too.

A. Chinese  

B. Beijing  

C. U.S.A.  

D. middle school

下列元件哪些属于真空断路器（）。

A.真空灭弧室

B.操动机构

C.电阻丝

D.晶闸管