Qúa khứ tiếp diễn nha mọi người, giúp tui với: 1.They (study)……………………. in the library when the fire alarm went off. 2. It (snow)……………………………. when I got up this morning. 3.Abert Einstein…………………………… ( show) his experiment when I came 4. Tom ( watch) ……………………TV while I (read)…………… books yesterday. 5. Hellen (wait) ……………………………for me at 7 pm yesterday 6. ……..he (work) …………………………..his way through college at this time? 7.He (teach)………………….. economics at Harvard when his dad arrived to live with him 8. The wind (blow)……………………….. very hard when I went out this morning. 9. He fell off while he (go)……………………… down the stairs. 10. . At this time last month, I (visit) ………………London 11. . All last week, they (repaint)…………………. their school 12. . When I (meet) ………….her, I (tell)……………… her about my family 13. . While Mai (skip)………… rope, Tien (play)…………. marbles 14. . Hoa and Nga (make)……………….. cakes between 3 and 5 yesterday afternoon 15. . While I (repair)…………….. the roof, I (fall)…………….. off ladder 16. . He (water)……………… the vegetable when I (come) …………………his house 17. . While we (have) …………dinner, the telephone (ring)………….. 18. . When I (see)……………. him, he (sit)……………. in the cofe 19. . While she (slice) ……………. beef, she (cut) …………….her 20. . From 4 to 6 yesterday afternoon, we (wait) ……………. for our teacher at the station