15. Nam is very lazy, so he failed his exam.

16. will you

17. She wishes she would work for that company in the future.

18. They spent 80 days travelling around the world.

19. It takes him an hour to teach his son Math a day.

20. won't they

21. A letter is being written to Anna.

22. My house has been built for ten years.

23. wasn't it

24. is it

25. It takes me thirty minutes a day to water the garden.

26. He spent four days finishing the report.

27. If David spoke English well, he could find a good job.

David wishes he spoke English well to find a good job.

28. My sister suggested holding a party next Sunday.

29. The teacher asked Smith not to copy David's test.

30. If it is hot, I won't go out.

31. Huy said his sister would visit him the next day.

32. Na's mother asked her what she was doing.

33. didn't they

34. aren't I

35. If you don't slow down, you will have an accident.

36. If the sea weren't rough, we could go swimming.

37. It's a year since she last ate meat. 

She last ate meat a year ago.

38. I was bought a dicitionary by my mother yesterday.

39. The faucet is going to be repaired by David.

40. If my son had time, he would go for a pinic.

15.nam is very lazy so he failed his exam.

17. she wished she workedforthat company 

21 a letter is being written to anna

22. my house have been built for 10 years

27. if david speaks EL well,hecould find a good job

      david wished he spoke El well tofind  a goodjob  

29. the teacher said smith not to coppy david's test

30. if it's hot, i won't go out 

31huy said his sister would visit him the next day

32 na's mother asked what she was doing

36. if the sea were't rough,we could go swimming

38. a dictionary was bought to me yesterday

39. the faucet is going to be prepaired by david

40 if my son had time, he would go for a picnic