=>
22. C ( often causes accidents -> bất cẩn)
23. A ( than -> so snahs hơn)
24. B while qktd
25. C whether liệu rằng
26. C while qktd
27. C HTHT -> Qkđ
28. B for -> HTHT
29. D để không bị làm phiền

30. A would you mind Ving
5/
31. has worked
32. I learn English so as to communicate with foreigners 
33. friendliness

34. It last rained here two weeks ago.
35. That old house has just been sold recently.

6/
36. one person
37. 3 competitions
38. It was held in the communal house yard about one kilometer away from the river.
39.  In the fire-making contest, two team members had to make fire in the traditional way.
40. Yes, they had to seperate the rice from the husk.