Em cần gấp ạ e cảm ưn

`Đáp` `án:`

11. I haven't enjoyed myself since your birthday party. 

12. My father hasn't seen his brother for nearly 20 years. 

13. Tom has not gone to Scotland for a year.

14. How long is it since you rode a bike?

15. I haven't gone swimming since I was in France. 

16. It's few years since you last tidied up this room.

17. He hasn't kept in touch with me for three weeks.

18. Mr. John last visited France in 1990.

20. It is three weeks since it last rained. 

21. This is the first time I have eaten this kind of food.

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Các công thức đổi HTHT - QKĐ

Loại 1: 

S + has/have + not + V3/ed + for/since + time 

--> S + last + V2/ed 

--> The last time + S+ V2/ed + was + time + ago

--> It is / has been + time + since + S+ (last) + V2/ed 

Loại 2: 

How long + has/have + S+ V3/ed?

--> When + did + S + V1?

--> How long is it + since + S+ V2/ed ?

--> How long ago + did + S + start / begin + to V / Ving? 

Loại 3:

S + has/have + V3/ed + for/since + time 

--> S + started / began + to V / Ving 

--> It is / has been + time + since + S+ V2/ed 

Loại 4: 

S + has/have + not/never + V3/ed + ... before

--> This/It is the first time + S+ has/have+ V3/ed

Loại 5:

When + did + S + last + V1?

--> When + was the last time + S + V2/ed?