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----- Nội dung dịch tự động từ ảnh -----
18. I am really sorry for my mistake. It was one that I
A. ought not to have made
B. mustn't make
D. had not to make
how
C. ought not to be making
19. A good student must know
A. to study effectively
B.
effectively
D. the way of efficiency in study
to
study
C. how to study effectively
20. Only after food has been dried or canned
A. that it should be stored for later consumption B. should we store for later consumption
C. should it be stored for later consumption
D. it should be stored for late consumption