问题描述: I left a backpack on the train to beijing the other day否定句疑问句和肯定回答否定回答 1个回答 分类:英语 2014-11-22 问题解答: 我来补答 I didn't leave a backpack on the train to beijing the other day.Did you leave a backpack on the train to beijing the other day?----Yes I did/no I didn't 展开全文阅读