2. I (walk) __was walking___ along the street when I suddenly (feel) ___felt__ something hit me in the back.

3. When we (drive) __were driving___ down the hill, a strange object (appear) __appeared___ in the sky.

4. How fast (she/drive) ___was she driving__ when the accident (happen) _happened____?

5. My mother (wait) __was waiting___ for me when I (come) __came___ home?

6. Mrs. Smith (invite) __invited___ Mrs. Quyen to have dinner while Mrs. Quyen (visit) __was visting___ the USA.

7. I (not want) __don't want___ to go with him because I (wait) _was waiting____ for a phone call.

8. The doorbell (ring) __rang___ while Tom (watch) ___was watching__ TV.

9. It suddenly (begin) ___began__ to rain while Linda (sit) _was sitting____ in the garden.

10. The lights (go) __went___ out while we (have) __were having___ dinner.