Rob2233 发表于 2017-2-23 21:45 9 x# e: G2 U6 _% O. 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,/ \% j7 g8 _% m4 }( G0 q* u! n# V
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.