are you still working in shanghai

问题描述:

are you still working in shanghai
--Are you still working in Shanghai?
--No,I'm working in Ningbo now.I_____in Shanghai for three years
A.worked B.have worked C.had worked D.was working
为什么不能用过去完成时

选B 过去完成时(past perfect)表示在过去某一时间或动作之前已经发生或完成了的动作或状态.它表示句子中描述的动作发生在“过去的过去”.现在完成时(past perfect)表示在现在某一时间或动作之前已经发生或完成了的动...