giúp mình bài này nha : Dạng bài tập : HTHT QKĐ : 1. I last ate raw fish when I was in Japan.  I haven’t __________________________________________________________________ 2. It's years since Mary last spoke French.  Mary hasn’t ________________________________________________________________ 3. It's ten weeks since since I last had a good night sleep.  I haven’t __________________________________________________________________ 4. He last paid taxes in 1970.  He hasn’t _________________________________________________________________ 5. I last ate meat 5 years ago.  I haven’t __________________________________________________________________ 6. It's 3 months since since the windows were cleaned.  The windows haven’t ________________________________________________________ 7. It's years since I took photographs.  I haven’t __________________________________________________________________ 8. I last watched TV on new years's day.  I haven’t __________________________________________________________________ 9. It's 3 months since he wrote to me.  He hasn’t _________________________________________________________ 10. The last time I was aboard was in the summer of 1978.  I haven’t __________________________________________________________ 11. It's ten years since that house was lived in.  That house ________________________________________________________ 12. I haven't seen him for 2 months.  I last _____________________________________________________________ 13. I haven't been to a concert for over a year.  The last time ____________________________________________________ 14. The last time I really enjoyed myself was your birthday party.  I haven’t ________________________________________________________ 15. It's nearly 20 years since my father saw his brother.  My father hasn’t __________________________________________________ 16. When did you learn to drive?  How long is it ____________________________________________________ 17. The last time I went swimming was when we were in Spain.  I haven’t ________________________________________________________ 18. You haven't tidied this room for weeks.  It’s weeks _______________________________________________________ 19. We started looking for a flat 2 months ago and we are still looking.  We have ________________________________________________________ 20. This is the first time I've been to a night club  I haven’t ________________________________________________________ 21. They have never heard such a thing before.  This is the first time ________________________________________________ 22. Noone has challenged his authority before.  This is the first time ________________________________________________ 23. She left university 2 years ago  It is _____________________________________________________________ 24. My mother was the most warm-hearted person I've ever known.  I have ___________________________________________________________ 25. I haven't been able to see them for over a year.  It is _____________________________________________________________ 26. It stared to rain at 2 o'clock.  It has ____________________________________________________________ 27. I have never been to the ballet before.  It is ______________________________________________________________ 28. John and Mary moved to Edinburgh twenty years ago.  It is ______________________________________________________________ 29. The police started looking for him two months ago.  For two months now the ______________________________________________ 30. I have never seen a dirtier-looking dog.  This is ____________________________________________________________