Rob2233 发表于 2017-2-23 21:457 O' y. V! r& f0 i/ 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, ! R, L, e* E( T0 Z. |* F/ X8 C这应该是比 ...
! |2 K6 x6 ]- o6 L
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.