3. Tina is able to speak Chinese.(改为同义句) 

Tina  Chinese.

2. No food in class.(改为同义句)

  in class.

1. We can wear hats in school.(改为—般疑问句并作肯定和否定回答)

5. We can eat in the dining hall. We can't eat in the classroom.(用but连接两个句子) 

4. We can wear hats in school.(改为否定句)

am,may,must,can t,mustn't

1.— you speak French?

 No,I , but Mr. Black .

2.— I use your knife?

  —Certainly.

3. —we go out and play football now?

  No. you . You finish your homework first.

4. She hear you clearly. Please speak a little louder.

5.—How long I keep this book?

 —You keep it for two weeks.

1.We study English together.(改为同义句)

 English together.

5. The doctor can do nothing to help the boy.(改为同义句) 

The doctor   to help the boy.

4. He has to work for ten hours every day.(就画线部分提问) 

   he to work every day?

3. She read the book under the tree yesterday afternoon.(改为一般疑问句) 

shethe book under ihc tree yesterday afternoon?