问题描述: The whole class is working hard preparing for the exams.为什么用preparing? 1个回答 分类:英语 2014-11-26 问题解答: 我来补答 working hard是插入语,主句为The whole class is preparing for the exams,所以is preparing意思是"正在准备",是现在进行时. 展开全文阅读