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11. My uncle said that picture was very nice.
12. The teacher asked Tom what he was doing then.
13. She asked me if I would be free the following day.
14. "Why are you learning English?" She asked me.
15. If Mrs.Ha works harder, she will get a lot of money.
16. Unless she hurries, she will miss the last train.
17. If you don't work hard, you can't pass the exam.
18. Why don't we attend the Brighton Language Center?
19. My father advised me to enroll in that college.
20. Peter asked Nam where he was working then.

III/
1. If you give up smoking ,you might gain weight. 
2. If we move to a cheaper apartment , we may be able to save some money.
3. If she doesn't stay awake in class, she won't be able to get enough sleep .
4. If they want to pass the exam succesfully, they must study harder.
5. If he wants to drive his car, he has to take a driving license.

IV/
1. bought
2. was
3. had sold
4.  passed 
5. could
6. would sell
7. had gone
8. didn't do