Rob2233 发表于 2017-2-23 21:45 - H+ D; a/ R) b/ p! F& v) X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,( Y+ T. y8 ?9 m- S4 G4 n" K- T" f
这应该是比 ...
8 Y( Q9 F% G8 `+ Y/ S1 j6 G# [" 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.