Rob2233 发表于 2017-2-23 21:45 ; W1 c. L- [& S8 I! c/ F" R6 P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,; e1 {% E: D1 W2 u% q$ m
这应该是比 ...
7 c" P9 x: {! b6 W4 O9 jthanks 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.