题目内容：

根据句意以及所给动词的适当形式填空

1.How high the mountain is! We have difficulty____   (breathe) the fresh air on the top of it..

2.Not only his parents but also Tom ____   ______(see) the film Titanic several times.

3.We must do everything we can ________________(prevent) haze. It’s bad for us.

4.The meeting about the South Sea of China ______     ____ live tomorrow(cover).

5.–I called you at 4:30 p.m yesterday, but nobody answered.

--Sorry, I _______   ____(try) out for the school basketball team at that time.