1. / My sister.....the meal at 7 p.m last night. A. were preparing B./ was preparing C. had prepared D. prepared 2. Since he moved to the other city, he......any friends. A.didn't meet B. haven't met C. hadn't met D. hasn't met 3. what ..........at that time? A. did you do B. do you do C. are you doing D. were you doing 4. / After Mary had done her homework, she ........to bed. A./ had gone B. has gone C. was going D. went

1.B

có dấu hiệu at 7pm và last night

=>QKTD

2.D

có since thì luôn cố định là trước since QKĐ và vế còn lại là HTHT

3.D

dhnb:at that time

4.D

1 sự việc sảy ra sau 1 sự việc trong quá khứ là cặp QKHT và QKĐ

mà had done là QKHT rồi

nên chọn went

`1B` was preparing

`->` Thì quá khứ tiếp diễn - at 7p.m last night : 

`(+)` S + was/were + Ving

`(-)` S + was/were + not + Ving

`(?)` Was/Were + S + Ving ?

`->` My sister ( chị của tôi) : số ít - was

`2D` hasn't met

`->` Thì hiện tại hoàn thành - since :

`(+)` S + has/have + PII

`(-)` S + haven't/hasn't + PII

`(?)` Has/Have + S + PII ? 

`->` He (anh ấy) : số ít - has

`3D` were you doing

`->` Thì quá khứ tiếp diễn - at that time :

`(+)` S + was/were + Ving

`(-)` S + was/were + not + Ving

`(?)` Was/Were + S + Ving ?

`4D` went

`->` Thì quá khứ hoàn thành - After + Quá khứ hoàn thành

`(+)` S + had + PII 

`(-)` S + hadn't + PII

`(?)` Had + S + V ?