Câu 21 : D . 1928
Câu 23 : A . 1945
Câu 24 : D . penicillin
Câu 25 : go
Câu 26 : was cooking
Câu 27 : . not to spend
Câu 28 :28. was
Câu 29 : has lived
Câu 30 : playing
Câu 31 : was built
Câu 32 : gets
Câu 33 : Mai is the youngest in the group.
Câu 34 : I asked them where they were going for their holidays.
Câu 35 : The luggage is so heavy that she can't carry.
Câu 36 :If he hadn't been tired, he could have scored some goals.
Câu 37 :I suggested taking the train.
Câu 38 : Lan used to stay up late when she was young.
Câu 39 : Do you spend 3 hours doing this task?
Câu 40 : Because I am short, I can't play basketball.
