The cleaners must prevent the street _____.

A．from getting dirty

B．to dirty

C．to get dirty

D．getting dirty

根据汉语提示填写单词。

1. The music ________(听起来) like birds singing.

2. If you get a ________(机会) to go there, please take it.

3. The little boy was _______(惊讶) at the beautiful fish he could see in the sea.

4. The sign here ________(警告) you not to smoke.

5. It' s not ________(允许) to take the books out of the classroom.

6. The story happened a few ________(世纪) ago.

7. These days the workers are busy ________(生产) this kind of medicine.

8. His parents always ________(鼓励) him to study hard.

9. Tom is very ________(自豪) of his new car.

10. His son is living ________(国外) now.