用括号内所给词的适当形式填空
1. The train arrived at _________ (exact) eight o'clock. It was neither earlier nor later.
2. I don't know how __________ (chat) on the Internet.
3. The doctor told my father to give up _________ (smoke).
4. His story kept us __________ (laugh) for a long time.
5. I used to_________ (study) by reading a lot.
6. The girl won the first price in the swimming competition. Her parents take _________ (proud) in her.
7. We can't help him. He can work out the problem by_________ (him).
8. The child was so_________ (terrify) that he couldn't say a word when he saw the large snake.
