1 bỏ ago
2 bỏ to - bỏ ago
3 read this novel for a week
4 written this book since last week
5 played badminton since 1986
6 played the piano since she was ten
7 been a doctor since he was 21
8 played soccer since last year
9 smoked for 2 years
10 written since she moved to England
11 worked in this factory since last month
12 planted flowers for 10 years