问题描述： he is swimming across the river.变否定句、一般疑问句、肯定回答、否定回答急需 1个回答 分类：英语 2014-10-23 问题解答： 我来补答 否定句：He isn't swimming across the river.一般疑问句：Is he swimming across the river?-Yes,he is.-No he isn't. 展开全文阅读
