there used to be walls around the city of beijing改为一般疑问句

分类: 作业答案 • 2021-12-01 17:08:43

问题描述：

答

Did there use to be walls around the city of Beijing?
首先used to be是表示过去总是...,所以一般疑问句的助动词要用过去式did,一个过去式就够了所以后面的就改成use to就O了.