1. có "last night" $\rightarrow$ dùng thì qkđ

$\rightarrow$ have just met/ met

2. có "since" $\rightarrow$ dùng thì htht

$\rightarrow$ have known/ was

3. có "many times" $\rightarrow$ dùng thì htht

$\rightarrow$ have walked

4. hđ này đng diễn ra thì hành động khác xem vào

$\rightarrow$ came/ was talking 

5. cấu trúc wish 

$\rightarrow$ didn't buy

6. có "every day" $\rightarrow$ dùng thì htđ

$\rightarrow$  call/complain 

7. cấu trúc wish 

$\rightarrow$  would be  / would have

8. $\rightarrow$ hadn't go

9. $\rightarrow$ arrived/ met

10. $\rightarrow$ can be mailed/ was

1. have just met/ met (do ở thời QK)

2. have known/ was

3. have walked (do có many times)

4. came/ was talking 

5. didn't buy (lùi 1 thì trong câu ước wish)

6. call/complain ( vì có everyday)

7. would be ( lùi 1 thời) / would have

8. hadn't go

9. arrived/ met

10. can be mailed/ was