11. not to speak
12. to explain/ listening
13. smoking
14. to disguise/ dressing
15. to wait
16. showing/ to work
17. walking/ resting/ to catch
18. understand
19. playing/ doing
20. to imform

21. smoking
22. to smoke
23. going- saying
24. writing/ waitng
25. to avoid being

26. giving/ speak
27. to persuade/ to agree
28. cleaning/ to do
29. shutting/ sitting
30. sneezing/ to sit
31. talking/ to finish
32. to give/ jogging
33. stopping
34. to make/ rubbing
35. answering/ ring

36. letting/ chase/ being
37. driving/ being
38. to start/ looking
39. lending/ to cash
40. Lying/ sitting
41. going
42. to show/ to use
43. going/ seeing

44.i suggest (telephone)---telephoning----------the hospitals before(ask)--------asking-------------the police(look)----------to look-------for him.
45. after (hear)-------hearing---------the conditions i decided (not enter)-----------not to enter-----------------for the competiton.
46.some people seem(have)------to have-----------the passion for (write)------writing---------to the newspapers.
47. he postponed me (make)-------making------------a decision until it was too late (do)----to do----anything.
48. he expects me (answer)----to answer----------by return but i have no intention of (reply)------replying-----------at all.
49.try (forget)---to forget--------it; It isn't worth (worry)---------worrying----------------about it.
50. there is no point in (remain)--remaining------in a dangerous place if you can't do anything (help)---to help---the people who have(stay)--stayed--there.

Bài tập 3:
1. Where/ you/ go? When/ you/ go? => Where are you going to? When are you going?
2. Who/ you/ go/ with? => Who do you go with?
3. How/ you/ get/ there? => How long does it take you get there?
4. What/ you/ do/ during the day? => What are you doing during the day?

Bài tập 2:
1. I was play football when she called me. => Was playing
2. Was you study Math at 5 p.m. yesterday? => studying
3. What was she do while her mother was making lunch? => doiing
4. Where did you went last Sunday? => do
5. They weren't sleep during the meeting last Monday. => sleeping
6. He got up early and have breakfast with his family yesterday morning.=> had
7. She didn't broke the flower vase. Tom did.=>break
8. Last week my friend and I go to the beach on the bus. =>went
9. While I am listening to music, I heard the doorbell. =>was
10. Peter turn on the TV, but nothing happened.=>turned