Rob2233 发表于 2017-2-23 21:45$ o4 L" _$ ?) d, e/ z: L
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,& u" q. B7 i$ a2 M5 W
这应该是比 ...
( e) A( a' E! G$ ~9 Rthanks 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.