Have you found your mother?Not yet By the time I got to here office,she____ A has left B had left

题目

Have you found your mother?Not yet By the time I got to here office,she____ A has left B had left
c left Dwas leaving

答案

选B,这是一个过去完成时.前面问找到我妈妈了吗?后面回答：还没,等我到了办公室,她已经离开了.到办公室已经是过去,他妈妈离开还在之前,可以看出到办公室之前就离开了,所以还没找到.