3. had left

4. didn't attend

5. to be helped

6. lending

7. not to sell

8. to open

9. not using

10. was driving

11. had bought

12. didn't write

13. have cleaned

14. was reading

15. weren't

16. taking

17. going

18. not to meet

19. not to make

20. told

21. showing

22. were watching

23. were building

24. didn't attend

II.

1. They let him use their car.

2. After the train had left, he arrived.

3.  Peter and Maria decided to go to the cinema.

4. Would you like a cup of coffee?

5. Before going to school, she had done her homework.

6. We want to play football with our close friends at weekend.

7. It is very nice to meet your parents.

8. My parents make breakfast for me at home.

9. I want you to travel by bus.

10. She enjoys walking in the rain.

11. To speak to him is easily.

12. Before he went to the cinema, he had bought a ticket.

13. They enjoy going shopping on Sunday mornings.

14. It is very exciting to read his books.

15. After she had eatten breakfast, she went to work.

16. He doesn't forget to turn off the light before going out.

17. When I arrived, Jack had left the office.

18. While I was having lunch someone rang the bell.