Rob2233 发表于 2017-2-23 21:45& u+ @! J7 [' K' b2 F7 a, Q
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, + e" }3 w) B2 r: D( r: E这应该是比 ...
: S3 Z& F+ C. G6 k5 S* `8 Uthanks 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.