根据句意和首字母完成单词。

1. My books are in the    b______ .

2. —W______ is my pen?  

    —In your pencil-case.

3. I often w______ TV in the evening.

4. He eats lots of v______ every day.

5. They like ______ (汉堡)for lunch.

6. What do you eat for ______ (早餐)?

7. Please b______ your homework to school tomorrow.

8. How many people are there in your f______ ?

9. Do you have any b______ or sisters?

10. Your watch is in your d______ (抽屉).

如图所示，一个轻质弹簧下端悬挂一个小铁片，当开关S断开时，铁片刚好与水银槽中水银接触．当开关S闭合后，铁片会

A．不动

B．陷入水银面以下

C．向上运动停止在空中

D．上下不停的振动