Rob2233 发表于 2017-2-23 21:45 3 E f. q8 c) K( _1 i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, : n7 L# l/ w) V1 |, {% X这应该是比 ...
4 H* `- a* ^. x; o$ A$ dthanks 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.