Answer:
I stopped corresponding with Ben a long time ago
→ I haven't corresponded with ben since long time
7. It’s almost 3 months since I last played badminton.
→ I haven’t played badminton since 3 months
8. Her sister didn’t meet her cousin a few years ago.
→ Her sister hasn't met her cousin since few years
9. I didn’t live in Tra Vinh when I was eight years old.
→ I haven’t lived in Tra Vinh when I was eight
10. We last talked to our form teacher three months ago.
→ We have not talked to our form teacher for three months
11. My brother stopped smoking four weeks ago.
→ My brother hasn’t smoking since four weeks
12. My teacher hasn’t talked to us since we left school.
→ My teacher last talked to us when we were leaving the school
13. My father hasn’t planted trees in the garden for two months.
→ My father stopped planting tress in garden from 2 months
14. I have not visited Uncle Tri since 2005.
→ I last visited uncle tri in 2005
15. She hasn’t written to John since August.
→ She stopped writing to john from august
16. They stopped producing this kind of toy a long time ago.
They haven’t produced these kinds of toys from years
17 . We last saw Mary when we left university.
We haven’t seen Mary since we left university
18. I last travelled by plane a year ago.
→ I haven’t travelled by plane from year now
19. We stopped communicating with each other by radio a long time ago.
We haven’ t communicated with each other by radio since long time
20. You last helped me when you graduated from college.
You haven’t helped me from when you were graduated from college