26. A

27. D

28. D

29. B

30. C

1. Beautiful clothes are worn on Tet holidays.

2. Her sister was taught English last year.

3. Bill and Ann weren't invited to the party.

4. The traditional dress were worn frequently by men and women.

5. Jeans are sold all over the world.

6. Her valuable jewelry was stolen last night.

7. The letters was read to all his friends yesterday.

8. Many beautiful places were visited in Ha Noi by Lan and her pen pal.

9. Our clothes were washed with a new detergent.

10. The dishes were washed by Mary everyday.

11. English is spoken in the United State.

12. The door was painted by Peter everyday. 
13. Some trees has been just planted by farmer.

14. This play will be forgotten in a few years' time.

15. A ticket has been just given my little sister.