问题描述： for 加一段时间,得用什么时态? 1个回答 分类：英语 2014-11-27 问题解答： 我来补答 多用于完成时态 I have not heard from him for a long time.也见用于其它时态：Edison was a leading inventor of the world for 60 years. 展开全文阅读
