The problem is we can arrive there before 6:00 tomorrow morning.
A. which
B. whether
C. when
D. that
网友回答
A. which
(答案→)B. whether
C. when
D. that
解析：考查表语从句。从句we can arrive there before 6:00 tomorrow morning.不缺状语不选when，只缺少起连接作用的词而主语是The problem所以只能选whether。句意：问题是我们是否能明天六点前到那。