____ he ___ go to work by ferry before the bridge was built?

问题描述:

____ he ___ go to work by ferry before the bridge was built?
a.Did; used to b.Did; use to
为什么选B?Did引导疑问,use就不用used了吗?

选A,used to do someting是一种语法,表示过去经常做某事!