Bài 1: 1. have learned

2. didn't work/weren't

3. want to pass/have to study

4. sent

5. was/think/have learned

6. went/hadn't enjoyed

7. was doing/met

8. notice/is

9. am having/had

10. am revising

11. have already begun

12. think/would do

13. will be/aren't

14. pass/will start

15. will go

16. can see/have become

Bài 2: 1. on

2. to/for

3. of

4. at

5. on/with

6. in

7. at

8. in

9. in

10. at

11. for

12. on

13. at/at

14. on

15. of

16. to

Bài 3: 1. This dish is brought to me by the waiter.

2. these postcards are sent to us by our friends.

3. This story was told by their grandmother when they visited her last week.

4. this train ticket was ordered by Tim for his mother.

5. The ticket was showed to the airline agent.

6. This cake was baked by Jim yesterday.

7. A new apartment is going to be bought next year.

8. These boxes were handed by the shop assistant to the customer.