用所给动词的适当形式填空。
1. He'll write to me as soon as he _____ (reach) Xian.
2. — _____ you _____ (see)the film?
    —Yes, I _____ (see) it two weeks ago.
3. Tom! _____ (not do) it like that next time.
4. They _____ (make) a lot of friends since they came to our city.
5. Young trees_____ (water) well every day.
6. The teacher _____ (talk) to my father when I got home.
7. Thirty bikes_____ (mend) by Uncle Wang last week.
8. Where's Kate? She _____ (go) to the library.
9. We can use computers _____ (send) messages.
10. Look at the dark clouds . It _____ (rain) soon.
11. When Kate came in, I _____ ( write) a letter.
12. We'll go to visit the Great Wall, if it _____ (not rain) tomorrow.
13. Listen! Who _____ (sing) an English song in the room?
14. Li Ping _____ ( do) his homework at six yesterday evening.
15. _____ you _____ (have) your lunch?
16. The Greens _____ (live) in the city since 1945.
17. I want to buy some presents for all my family, but I _____ (not choose) any yet.
18. Tom _____ (watch) TV while his father was reading.
19. China _____ (change) a lot since 1978.
20. The machine _____ (make) in China in 2002.