在过去三年里英文

In past three years

in the past three years, I have been the commissary in charge of sports and deputy monitor of the class, my capability has been given lots of training when I was trying to fit for my position, the experience has provided me sufficient confidence to stand here today.

In the past three years,I occupied the commissary in charge of sports and deputy monitor,which trained me a lot and made me have enough self-confidence to stand here.

In the past three years we have made a great progress.

in the past three years与现在完成时连用。

During the past three years