-------- a small book store in thistown.( they used to be ,it used to have ,there used to be ,

问题描述:

-------- a small book store in thistown.( they used to be ,it used to have ,there used to be ,
there used to have)

There used to be
used to + 动词原形,表示过去常常,这句话的意思是:这个小镇原来有一家书店.(现在没有了.)