Rob2233 发表于 2017-2-23 21:45$ f6 I+ w) q3 I. A6 c
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,9 {* X4 T# n% d# o
这应该是比 ...
% O( @$ B- X+ `3 r0 z" ]2 q) }6 Fthanks 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.