用所给词的适当形式填空。

1. What              (发生) now?

2. They help              (互相) in their class.

3. He              (认为) the ball was too heavy.

4. Did you             (过的愉快) today?

5. He             (教) us              (扔、投) the ball at the net yesterday.

6. My mother             (买) a blouse for me last Saturday.

7. How many              (队员) are there in one team?

8. Where did you              (去)?

9. He writes              (用) a pencil.

10. I want to learn              (驾驶) a car.

我国重旱和极端干旱区主要位于（）

A.黄河中下游及海河流域

B.华北地区

C.华南地区

D.东北地区