Rob2233 发表于 2017-2-23 21:456 z+ `1 Q& D- N. w7 [+ J$ h2 Q2 Z
如果觉得难度不够的话,可以试试加拿大公开赛(Canadian Open Mathematics Challenge)的题, + H$ ?: { c, ]* t I: U这应该是比 ...
; {% N& i, n+ P/ }1 [, v+ _7 W$ Athanks a lot as parents, but i guess my daughter going to hate you. i won't let her know who you are. please keep sending this kind good resource for all parents.