Here are the correct answers for each blank in the exercise:

1. We (not see) **haven't seen** her for a long time.
2. My family (live) **has lived** in Thanh Hoa City since 2010.
3. They (not finish) **haven't finished** their homework yet.
4. He (write) **wrote** this book for children last year.
5. Yesterday when I came to see Peter, he (do) **was doing** his homework.
6. He (live) **has lived** in Thanh Hoa for ten years.
7. They (work) **were working** when she came yesterday.
8. They couldn't help (laugh) **laughing** when they heard the little boy singing a love song.
9. Toshico had a mechanic (repair) **repair** her car.
10. My family (have) **would have** a better life if we move to that city.
11. How long (learn) **have you learned** your daughter’s English?
12. Tom (already finish) **has already finished** his homework.
13. We (study) **have studied** Korean for two years.
14. We are from French. We (be) **have been** there for 20 years.
15. I (live) **have lived** here since 1970.
16. If I (take) **take**, it will take me 5 minutes to walk to school last year.
17. "Do you mind if I (work) **work** overtime?" asked the boss.
18. She has never known how (fry) **to fry** a steak.
19. I don't fancy (go) **going** out tonight.
20. I would love (join) **to join** the party with you.
21. He enjoys (have) **having** a bath in the evening.
22. She (talk) **was talking** during the film.
23. Can you (give) **give** me a hand?
24. My brother (suggest) **suggested** that I (have) **have** dinner early.
25. My brother (work) **has worked** for this company for nearly 20 years.

Feel free to ask if you need any further assistance!