问题描述: He was a waiter for two years before he went to college 改一处错误 1个回答 分类:英语 2014-10-26 问题解答: 我来补答 He had been a waiter for two years before he went to college .过去的过去用过去完成时~希望帮到lz~ 再问: She can't do the work,she needs your help. She can't do the work----------your help. She can do the work----------your help. 展开全文阅读