She did her work _______ her manager had instructed.A.as B.until C.when D.though

题目

She did her work _______ her manager had instructed.A.as B.until C.when D.though
个人感觉 A B C 都差不多呀,区别在哪?

答案

选A 啊
只有A时间对 因为manager had instructed 用过去完成时表示先于She did her work过去式的时间,B.until C.when主句和从句要用一样的时态.