1, Last night I lost my key  so I called my roommate. (QKD)

2, I've lost my keys so I've found them now (HTHT)

3, She has visited Thailand three times (HTHT+ số lần)

4, She had visted Thailand three times last year (QKHT+ số lần)

5, I has known my great grandmother for a few year but she died when I was 6 years old

6, I has known Tommy for a long time since we were kids

7, He plays piano at school but he doesn't like it (HTD)

8, He has play piano since he was small (HTHT+ since+ QKD)

9, We finished the test last week (QKD)

10, We have already finished the exam (HTHT có already).
CHẤM ĐIỂM NHA.