5.It's over 20 years since he last went back to his village.

*Vì $V_{2}$ của been là was/were, mà was/were trong trường hợp này nghĩa không ổn lắm, nên mình nghĩ đổi thành went sẽ hay hơn.

6. The boys found the journey to the village very interesting. 

*Xem lại đề, chủ ngữ sai.

7. We haven't gone to a cinema for 2 years.

8. She has lived here since she was five

9. I last saw him in 1990.

10. I started cooking for the party 3 hours ago.

5. It's over 20 years since he last was back to his village.

6. Xem lại đề.

7. We haven't gone to a cinema for 2 years.

8. She has lived here since she was five.

9. I last saw him in 1990.

10. It's 3 hours since I last cooked for the party.