用动词的适当形式填空。

1. While we _________ (wait) for the bus, a girl _________ (run) up to us.

2. I _________ (telephone) a friend when Bob _________ (come) in.

3. Jim _________ (jump) on the bus as it _________ (move) away.

4. We _________ (test) the new machine when the electricity _________ (go) off.

5. She _________ (not want) to stay in bed while the others _________ (all, work) in the fields.

6. While mother ________ (put) Cathy to bed, the door bell ________ (ring).

7. As I _________ (walk) in the park, it _________ (begin) to rain.

8. Even when she _________ (be) a child she _________ (already, think) of becoming a ballerina

    (芭蕾舞演员).

9. It was quite late at night. George _________ (read) and Amy _________ (play) her needle when

    they _________ (hear) a knock at the door.

10. There _________ (be) a group round the fire when they _________ (reach) it. An old woman

       _________ (sit) on the ground near the kettle; two small children _________ (lie) near her; a 

      donkey _________ (bend) his head over a tall girl.