1. 用所给单词的适当形式填空。

1. （1） They  (watch) TV from 8:00 to11:00 last night.

3. （2） The students(not sweep) thefloor. They were studying English.

5. （3） He always thinks about (go) tothe moon by spacecraft.

7. （4） It's polite   (say) hello to theold when we meet them.

9. （5） This is the  (stupid) mistakethat I've made in all my life!