Turn on the first for one min and then turn it off.4 s2 C0 w& f3 Z) \
Turn on the 2nd for five min and then turn it off. ' \6 Y' o! z1 }% J0 [8 P# I z! f" tTurn on the 3rd and leave it on.% _: Z! v7 p8 g" |. ?+ t0 v
And then go upstairs right away. 7 Y7 P) w+ X8 ^, u$ B1 V2 E# L8 o( J F, v- N
Find the answer by using your fingers and eyes # F9 g& B4 n/ X, t ^) @这只是一个智力问题,不象是电工问题。
原帖由 老警察 于 2009-1-16 07:12 发表 % M7 w) z. i" t) j
Turn on the first for one min and then turn it off. 6 e+ ^; q( p! n& @, w/ S4 HTurn on the 2nd for five min and then turn it off. T* P# O! C* C; y# S
Turn on the 3rd and leave it on. ' v$ h: U u! f; {And then go upstairs right away.4 n' s5 P9 n2 L2 k$ @' x