9. a

10. a

11. c

12. b

13. a

14. d

15. c

IV/1. The letters are delivered by Mr. Hai everyday.

2. The tickets are often bought by the children at the box office.

3. Their homework is usually finished before bed time.

4. Our exercises are corrected by the teacher today.

5. The shows of music are often watched on TV.

6. A written test is done today.

7. The Picasso's exhibition is always seen.

8. The streets are cleaned by the workers everyday.

9. Many accidents are caused by careless driving.

10. The river bank is covered by weeds.

11. Letters are typed by Mary in the office.

12. 2 newspapers and 1 magazine are bought everyday.

13. Many flowers are planted in the garden.

14. A lot of money is spent on advertising everyday.

15. English is spoken in almost every corner of the world.

16. 30 bottles of milk are drunk by the children every month.

17. After class, the chalk board is always erased by one of the students.

18. Chinese is learnt at school.

19. A great of property is destroyed by hurricanes this year.

20. The room is cleaned every day.

V/1. are/reach

2. comes

3. came/left

4. would take

5. am attending/was attending

6. arrive/will wait

7. had lived

8. visited/was