There used to be a clear river across the city 改一般疑问句并做否定回答

问题描述:

There used to be a clear river across the city 改一般疑问句并做否定回答
改成— ______ ________ _____ __________ ______ a clear river across the city?
—No,_____ _____

Did there use to be
there didn't