It was foolish of you to take a taxi you could easily walk there in five minutes.
A. while
B. when
C. since
D. before
网友回答
A. while
(答案→)B. when
C. since
D. before
解析：考查状语从句引导词. A.当……时候，强调主从动作同时发生 B. 当……时候 C. 自从……以来 D.在……以前。根据题意，当你能轻松的在五分钟内走到那儿的时候，打出租车简直太蠢了。故选B。