什么情况下用had been doing

问题描述:

什么情况下用had been doing
i (work)_____ here for three years since i left the corporation UMBRELLA 答案是had been working
为什么要用被动语态?

答案错了.
用现在完成时或现在完成进行时.have worked/ have been working.
had been working 过去完成进行时,表示过去的过去正在进行的动作.