----Did you your friend when you were in Beijing?---No. But I my aunt’s during my stay t

问题补充：

----Did you your friend when you were in Beijing?

---No. But I my aunt’s during my stay there.

A. call on; called on

B. call at; called at

C. call on; called at

D. call at; called on

答案：

A. call on; called on

B. call at; called at

(答案→)C. call on; called at

D. call at; called on

解析：考查短语：call on sb 拜访某人，call at 拜访某地，句意：当你在北京的时候你拜访了你的朋友了吗？没有，但是在我停留在那的日子我拜访了我姑姑家。所以选C。