—Who telephoned you just now?
— don’t know. I was about to answer the phone when it .
A. rang up
B. rang off
C. hung on
D. rang back
网友回答
A. rang up
(答案→)B. rang off
C. hung on
D. rang back
解析：考查短语辨析。rang up 打电话，rang off 挂断电话，hung on 稍等，别挂断，rang back 回电话，句意：刚才谁给你打电话了？不知道，我刚要接电话正在那时它挂断了。所以选B。