4. He was very enthusiastic about going to the Great Wall.

3. He made no response to the thing.

2. I decided to learn English just for fun.

5. take on

3. burst into　　　　 　　4. make room for

15. -I’m sure Andrew will win the first prize in the final.

-I think so. He 　_______ for it for months.

A. is preparing　　　　 　 B. was preparing

C. had been preparing　 　 D. has been preparing

14. _______ environmental damage is done, it takes many years for the ecosystem (生态系统) to recover.

A. Even if　 　　　　　 　B. If only　 　　　　　

C. While 　　　　　 　　　D. Once

13. -Could you do me a favour?

-It depends on 　_______ it is.

A. which　　 　　　　　 B. whichever 　　

C. what 　　　　　 　　D. whatever