Question

There ___ a museum here. A.used to B.used to do C.used to have D.used to having

Answer 1

A

there be 结构本身就表示“有”（存在有）的意思，为什么后面还要用have呢？
只是考虑这个be用什么形式，used to be 表示“过去曾经”

所以there used to be a museum here. 这里以前有个博物馆。

Answer 2

C

Answer 3

C

Answer 4

应该是used to be