Rewrite the following sentences, keeping the meaning unchanged

I. Rewrite the following sentences, keeping the meaning unchanged.

1. How long is it since you came here? 
->When... 
 2.When did your mother watch that play? 
->How long..
3.How long is it since you met each other?
->when have.... 
4. When did John buy the car?
->how long is it... 
5. How long is it since Tom left school?
->when... 
6. When did you read that novel?
->how... 
7. How long has she done that exercise?
->when did... 
8. When did you phone her?
->how long
9. How long have his parents visted him ?
->how long ago... 
10. How long has your aunt lived in that city? ->How long ago... 
11. When did you first know him? 
→How.... 
12. When did you start the project? 
->How long...
 13. How long have you learnt French? 
→How long ago..
 15. How long has your sister worked for this company? 
->How long ago.
16. I haven't seen her for a long time.
-> I didn't.. 
17. We haven't written to each other since 2001.
->We didn't.
18. I last wrote to my uncle in July. 
->I haven't... 
19. I haven't heard him since August.
 ->The last time...
20. Lan hasn't written to Maryam for two months.
-> Lan didn't..
21. The last time I went to that restaurant was 4 days ago.. 
→I last
22. Minh last wrote to Nga five months ago.
→Minh has.... 
23. His parents haven't visited that place since they were students. 
->the last time.
24. The last time I went to Japan was 4 days ago.
.-> I last 
25. I haven't heard this story for a long time. ->The last time.. 
26. Maryam hasn't written to Lan since their first meeting. 
->Maryam last..
27.I haven't seen his sister since last month.
 ->I didn't...