We started working here three year ago
A. We worked here for three year
B. We have no longer worked here for three years
C. We have worked here for three years
D. We will work here in three years
`Cấu trúc : S + strarted + V - i n g + thời gian`
`hoặc : S + have / has + since / for + khoảng thời gian`
`A và D sai thì . B sai nghĩa.`