27. A inventors.

28. A electric light bulb.

29. D after. 

30. A in.

31. turn.

32. A said.

33. C--> Would.

34. A--> was waiting.

35. C--> will be waiting ( thì hiện tại tiếp diễn).

36. A--> to have ( plan to do sth).

37. After I had had my breakfast at home, I went to school.

38. Oliver said to Chau that she was going to VietNam the following day.

39. Despite the terrible storm, no one was injured.

40. If to day was Sunday, I wouldn't have go to school.

=>
IV/
27. A nhà phát minh
28. A bóng đèn điện
29. D sau khi
30. A in + năm 
31. C plan to V
32. A said

V/
33. C -> would
34. A -> was waiting
35. C -> be waiting
36. A -> to have

II/
37. After I had had breakfast at home, I went to school.
38. Olive said to Chau that he was going to Viet Nam the following day.
39. Despite the terrible storm, no one was injured.
40. If today were Sunday, I wouldn't have to go to school.