Rob2233 发表于 2017-2-23 21:45 6 y0 V- h- E/ s& T. r; ?3 B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, & }/ @% s ^6 ?( y9 W& X1 A3 a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.