Rob2233 发表于 2017-2-23 21:45 2 i; @* l$ Y4 ~ G6 F, z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, I; e& r# n9 e n; ]. G H4 d这应该是比 ...
4 `0 D% m% `* F4 M. ~: S$ d0 [8 Gthanks 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.