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

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

6. We haven't met for a long time.

7. How long have you had it?

8. I have never had such a delicious meal before.

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

10. It is 3 days since I last took a bath.

Ex6:

1. cutted -> cut

2. working -> worked

3. haven't -> hasn't

4. eat -> eaten

5. hasn't -> haven't

6. câu này đúng

7. since -> for

8. since -> for

9. for -> since

10. hasn't -> haven't

Ex7:

1. hasn't played

2. are attending

3. haven't had

4. haven't seen

5. is having

6. is happening

7. have - realized

8. has finished

9. is composing

10. are having

Ex8:

1. She has lived in Ha Noi for 2 years.

2. He has studied English since he was young.

3. This is the first time I have ever eaten this kind of food.