5. The problem is so hard that he can’t work it out.(同义句转换) 

The problem is for him work out.

3. People should do a lot of things for the Olympics. (改为否定句) 

People a lot of things for the Olympics.

2. We wanted to raise money for Project Green Hope.(对画线部分提问) 

you to raise money for?

四、句型转换。(20分)

1. You’re too young to join Oxfam Trailwalker.(改为同义句)

You’re not Oxfam Trailwalker.

10. He (grow) vegetables before he became a businessman.

9. Nobody (know) the number of the workers so far.

8. — Did you notice anybody enter the building just now?

  一Sorry,I (cut) down the tree in the garden.

7. It’s a little difficult for us (achieve) our dream right now,but we should never give up.

6. I'm thinking of (join) the writing competition.

5. He always (try) his best to do everything well when he was at school.