问题描述: This is ____ that we mustn't waste time A what B because C why D so 1个回答 分类:英语 2014-10-13 问题解答: 我来补答 B because A,D首先可以判断不对 C why这里不能与that 连用 可以是This is why we mustn't waste time. 展开全文阅读