—Why do you look worried?
— Because what I am really concerned about is my friend can do me a favor or not..
A. although
B. whether
C. when
D. where
网友回答
A. although
(答案→)B. whether
C. when
D. where
解析： 考查表语从句，句意：你为什么看起来很担忧？因为我的确关注的是我的朋友是否会帮助我还是不帮。根据句意应用关系词whether，选B。