Chia các động từ sau ở thì Quá khứ đơn, Quá khứ tiếp diễn và Quá khứ hoàn thành ⇱
1. When the police (arrive) (1) , the car (go) (2) .
2. While we (do) (3) a sight-seeing tour, our friends (lie) (4) on the beach.
3. They (eat) (5) everything by the time they (arrive) (6) at the party.
4. While Tom (play) (7) the piano, his mother (do) (8) the washing-up.
5. I (go) (9) after they (finish) (10) their work.
6. The light went out while I (have) (11) dinner.
7. He (do) (12) nothing before he (see) (13) me.
8. When they (get) (14) the station, the train (leave) (15) .
9. The house (catch) (16) fire while they were sleeping.
10. While Tom was reading, Amely (watch) (17) a documentary on TV.
11. The burglar (open) (18) the safe when he (hear) (19) footsteps. He immediately (put) (20) out his torch and (crawl) (21) under the bed.
12. Last night I (drop) (22) a plate when I (do) (23) the washing-up. Fortunately it (not/break) (24) .
13. Mary and I (dance) (25) the house when the telephone rang.
14. I (open) (26) the letter when the wind (blow) (27) it out of my hand.
15. The boy fell and hurt himself while he (ride) (28) a bicycle.