用所给单词的适当形式填空。
1. Jack told Tom that he ______ (prepare) for the exam those days.
2. It's important ______ (learn) English well.
3. Both of the sweaters are nice. I can't decide which one (choose) ______.
4. I think she's good at ______ (skate) and she's an excellent skater.
5. We try not ______ (be) late for work, but sometimes the traffic is really heavy.
6. If you don't show your ticket , I ______ (not let) you get into the cinema.
7. They are______ (talk) about the football match on the phone.
8. He isn't good at ______ (study) English. He needs a teacher to teach him at home.
9. I saw them ______ (swim) in the river when I walked there.
10. They______ (watch) the World Cup when I arrived there.