Rob2233 发表于 2017-2-23 21:45 - P, k, {) S$ t/ N d( 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,; u% c5 J o, T' H3 A8 \! P: B& `, u
这应该是比 ...
7 S! m; p, s- |/ 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.