Question

By the time Jack returned home from England, his son _______ from college. A．gra...

By the time Jack returned home from England, his son _______ from college. A．graduated B．has graduated C．had been graduating D．had graduated

Answer 1

D

试题分析：句意：当杰克从英国回家为止，他的儿子已经从大学毕业了。by the time …当……的时候，…… 通常引导一个时间状语从句，表示“到……的时候”主句则表示在此时间之前某个事件已完成。值得注意的是，当从句用过去时时，主句通常用过去完成时。选D。