39. A I haven’t talked to him for 5 months.

-> S + last + V2/ed + for + khoảng thời gian + ago = S + have/has + not + Vpp + for + khoảng thời gian.

40. B They used to go to school by bike when they were young.

-> used to + Vinf: đã từng làm việc gì đó trong quá khứ nhưng bây giờ không còn nữa.

39. I last talked to him 5 months ago.

A. I haven’t talked to him for 5 months.

B. I haven’t talked to him since 5 months.

C. I started talking to him for 5 months.

D. I started talking to him for 5 months ago.

Giải thích:  Loại C và D vì nó sai nghĩa với câu hỏi, Loại B vì không có since 5 months.

40. They often went to school by bike when they were young.

A. They used to went to school by bike when they were young.

B. They used to go to school by bike when they were young.

C. They are used to go to school by bike when they were young.

D. They are used to going to school by bike when they were young.

Loại C và D vì không có tobe, loại A vì sau used to là V.