6. 参与;发挥作用        

5. 植树        

4. 处于危险中        

3. 业余时间        

2. 活到200岁        

1. 在电脑上        

4. Jim is going to swim this afternoon. (改为一般疑问句，并作肯定回答)

一        Jim        this afternoon?

—Yes,          .

3. I don't know how I can do better at school. (改为简单句) 

I don't know how           better at school.

2. We are going to play football next Saturday. (对画线部分提问)

           you going to      next Saturday?

1. He is a doctor now. (用when he grows up改写句子)

He           a doctor when he grows up.