Rob2233 发表于 2017-2-23 21:45 ! w6 x; t* n" p6 T( U) {6 c8 N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, 0 N' s4 @% k. c( L' l L0 o8 E这应该是比 ...
& ] C. e, v- I6 v1 ithanks 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.