1) Give the corect form of the verbs in the present perfect.
1. Tom(see)............this film before.
2. I(finish)............my exercise already
3. They(live)...........here since 1990.
4. My father(just wash)...........his car.
5.The students(discuss)..........the question  recently.
6.Mary(never, be)...............to Ha Noi.
7. We(know)..................each other for 5 years.
8. So far we(learn)........five lessons.
9. We(be)..............pen pals for a long time.
10. They(stay)..........here since last week.