Rob2233 发表于 2017-2-23 21:45 & V. m( E8 f: t7 Y: n& ?8 k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,. g7 z! r' ?; N
这应该是比 ...
5 k% ~1 H) Q2 X8 P/ Y% Dthanks 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.