Rob2233 发表于 2017-2-23 21:45 . Q% e, n7 `6 G' I. k: p8 X N7 H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, 7 @7 C* F/ p- @+ c3 y这应该是比 ...
# i8 M' n& y w- K2 W
thanks 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.