Giải ra vì sao lại chọn đáp án đó

Giải ra vì sao lại chọn đáp án đó
7. Yesterday Ann introduced me to her husband. As I saw him, I ______ that I ______ him before. We went to primary school together.

A. knew / met        B. had known / had met         C. knew /had met     D. had known / met

8. I _______ you sooner if someone _______ me you were in the hospital.

A. would visit / told       B. will visit /tells       C. had visited / would have told       D. would have visited / had told

9. On the way to work, Tom met his former teacher.

A. When Tom was meeting his former teacher, he went to work.

B. Tom was going to work when he met his former teacher.

C. While Tom was going to work, he was meeting his former teacher.

D. By the time Tom went to work, he had met his former teacher.

10. He read a newspaper during breakfast.

A. After he had read a newspaper, he had breakfast.

B. Before he read a newspaper, he had had breakfast.

C. While he was having breakfast, he read a newspaper.

D. When he was reading a newspaper, he had had breakfast.

11. Bob drank some milk and then went to bed.

A. Bob went to bed after he had drunk some milk.

B. After Bob had gone to bed, he drank some milk.

C. Before Bob drank some milk, he had gone to bed.

D. While Bob was drinking some milk, he went to bed.

12. After four years abroad, he returned home as an excellent engineer.

A. After he studied for four years abroad, he returned home as an excellent engineer.

B. After he had studied for four years abroad, he returned home as an excellent enginee

C. After he studied for four years abroad, he had returned home as an excellent engineer.

D. After he has studied for four years abroad, he returned home as an excellent engineer.