同时进行 （猜猜看）

Sunday, August 24, 2008

有一种东西，上升的同时会下降，下降的同时会上升。请问这是什么？

Test said...: wao.......tat's hard....

i still don hav the answer....=.=; August 24, 2008 at 5:47 PM
kayunky said...: yea... it's hard... try to think about it or perhaps, you may ask your frens to think about it...; August 24, 2008 at 10:42 PM
Jinny Lim said...: 翹翹板; September 5, 2008 at 1:11 PM
kayunky said...: 答案出来了！就是翹翹板！; September 18, 2008 at 11:17 PM