题目内容：

After her husband had gone to work and the children ___to school,she went upstairs.
A.had sent
B.were sent
C.had been sent
D.were sending
这句话中为什么选C,不选B

优质解答

句中有个and
而and连接的两个句子要求前后时态一致
and前的那句her husband had gone to work 中had gone是过去完成时
所以and后面那句the children ___to school也要用过去完成时,即要用had been sent
选C.