Exercise 1: Chia dạng đúng của động từ trong ngoặc ở thì quá khứ hoàn thành.

1. Yesterday they went home after they (finish) their
2. When we came to the stadium, the match (already start)                         
3. Many people (move) to the new place before the storm
4. I sat down and rested after they (go)                
5. Before he died, he (be) ill for several
6. Last night before he watched TV, he (do) the exercise.
7. She went to the department after she (clean) the floor.
8. When I got to the party, they (go)
9. By the time the police arrived, the house (be) burned down.
10. By last year, twenty schools in this province (be)