B.
24. Has ... come
25. Lived / has lived
26. Have studied
27. Has given / are doing
28. Have known / was
29. Has driven / knew
30. Went / had finished
31. Had already begun
32. Hadn't eaten
33. Sat / rested
34. Watched / had done
35. Went
36. Had gone / went
37. Went / had called
38. Had taught / left
C
1. has studied ( hiện tại hoàn thành - for three years )
2. will have finished ( by next month ->tương lai hoàn thành )
