Rob2233 发表于 2017-2-23 21:45 $ Q" D6 w/ q% L: Q, j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,9 \7 C% b! u: b3 ^( I
这应该是比 ...
- F+ H" r# H6 V* ] ^+ J3 Y7 H& m
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.