按要求完成下列各题。
1. sing（名词形式）____________ 2. watch（第三人称单数）____________ 
3. write(名词形式) ____________ 4. go（第三人称单数）____________
5. do（现在分词）____________ 6. can not（缩写形式）____________
7. right（对应词）____________ 8. see（现在分词）____________
9. let’s (完全形式) ____________ 10. swim（现在分词）____________

He was always _________ about things. (    )

A．thinking

B．think

用所给词的正确形式填空。
【小题1】We should stop _________ (throw) rubbish into rivers.
【小题2】In the past, the Earth _________ (be) clean and beautiful.
【小题3】My brother is __________ (plant) trees in the backyard.
【小题4】The Earth __________(get) sick now.
【小题5】We shouldn’t __________ (cut) down so many trees.

句子改错
1. What are you do?
___________________________
2. He is good to sports.
___________________________
3. Lily is at my class.
___________________________
4. He is from Chinese.
___________________________
5. Peter is looking at the photoes.
___________________________

I’m ________ an e-mail.  (    )

A．writing

B．write

C．writting