－Excuse me does Mr Smith’s son live here?－He be here but he has moved.A. has to B. used

问题补充：

－Excuse me, does Mr Smith’s son live here?

－He be here, but he has moved.

A. has to

B. used to

C. tried to

D. happened to

答案：

A. has to

(答案→)B. used to

C. tried to

D. happened to

解析：used to do sth表示过去常常做某事而现在不做了。根据题意史密斯先生已经搬走了，以前的动作不复存在，故选B.