问题描述: 请问because,as,since.三个单词用于原因条件状语从句有什么区别 1个回答 分类:英语 2014-11-04 问题解答: 我来补答 He was busy,so he didn't come.可以变成以下句型:1 As / since he was busy,he didn't come ------从句在前面.2 He didn't come because he was busy -------从句在后面.3 He didn't come,for he was busy -------从属句在后面,用逗号隔开.这就是你想知道的区别. 展开全文阅读