【题目】I first met Lisa three years ago. She ________ at a radio shop at the time.
A.has worked
B.was working
C.had been working
D.had worked

【答案】B
【解析】句意：三年前我第一次遇到Lisa，那时她在一家收音机店上班。此处表示过去某个时间正在做的事，故选B。