1. arrived, had studied
2. made, had finished
3. was practicing, came
4. prepared, was raining
5. was playing, was watching
6. called, was doing
7. read
8. met
9. came, was cleaning
10. got, was starting
*Hành động đang diễn ra trong quá khứ thì dùng QKTD
Hành động xen vào thì dùng QKĐ
*Dấu hiệu thì QKTD: at + giờ chính xác + thời gian trong quá khứ, at this time yesterday,...
*Dấu hiệu thì QKĐ: last, ago, yesterday,...
*Hành động diễn ra trước một hành động trong quá khứ thì dùng QKHT