Rob2233 发表于 2017-2-23 21:45/ A: Z& F) { V4 Y3 A' 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,' N6 Y1 ?: X" M4 N I- v- S% L6 B
这应该是比 ...
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thanks 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.