Rob2233 发表于 2017-2-23 21:450 R4 N) o0 G% U% p* H
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% ]8 f$ b) v6 s; z$ s4 d
这应该是比 ...
% n" i: k' ]; O( |9 E2 n- Nthanks 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.