Rob2233 发表于 2017-2-23 21:45 $ H( F J+ I0 M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, & m. V6 F( [% _) G# X4 z2 U这应该是比 ...
" @* H, n5 X5 d! V7 S" l1 Athanks 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.