i know!公仔箱論壇0 _+ A. D- |+ ]
when they can have 15 mins discussion.5.39.217.770 u5 y0 f' P2 ~
make 1 of them to do a specific job whcih is counting
3 o% q7 q+ d6 i- S1 f/ ~only him can turn on off off the light.
4 \4 P7 B" S' n% s& q) h! q公仔箱論壇Basically, if you are the first time to get in the room, turn on the light,
! f0 T( t' t M9 T9 x$ s公仔箱論壇then wait for "the special man" to turn the light off....
" `+ v$ t4 Q& }; U" Ttvb now,tvbnow,bttvbwhen "the special man" count in up to 30 (included himself)0 l( k0 X; m& i
then it is done! |