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

By the time Jackreturned home from England, his son.      fromcollege.

   A.graduated                   B. has graduated

   C. hadbeen                     D.had graduated

试题答案

【答案】

D

【解析】考查动词时态，Bythe time 截止到过去某时间为止做了某事，用过去完成时态。 A是一般过去时；B是现在完成时；C是过去完成进行时。根据句子意思“截止到Jack从英国返家，他的儿子已经大学毕业了。