Ex3:

1.cutted->cut

2.working-> worked

3.have->has

4.eat->eaten

5.has->have

6.

7.since->for

8.since->for

9.for->since

10.

Ex1. - has been

- has not had

- has not played

nói chung là thì hiện tại hoàn thành hết ạ

Ex2.

1.She hasn't come back home for 4 years.

2. He has worked as a bank clerk for 3 months.

4. I haven't had my had my hair cut since November

5.We haven't called each other for 5 months

6. We haven't metr each other for a long time

7.How long have you had it?

8. I have never had such a delicious meal

9. The last time i saw him was 8 days ago

10.It is three days since I last took a bath

Ex 3. 

1. cutted -> cut

2.working-> worked

3.haven't-> hasn't

4. eat-> eaten

5.hasn't -> haven't

6. o

7. since-> for

8. since-> for

9.for-> since

10. hasn't-> haven't