-Do the Smiths live next door to you?---No but they .A. used to B. used to doC. are us

问题补充：

---Do the Smiths live next door to you?

---No, but they .

A. used to

B. used to do

C. are used to

D. used to be

答案：

(答案→)A. used to

B. used to do

C. are used to

D. used to be

解析：be used to sth习惯于某事;used to do sth过去常常做某事. sth be used to do sth某物被用来做某事。句意：史密斯一家住在你们隔壁吗？——不，但是他们过去是。结合语境可知选A。