Rob2233 发表于 2017-2-23 21:45 4 f' z0 b8 R) L# o+ c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 S. ^; H' n/ h9 o' N2 h1 `
这应该是比 ...
2 {# j$ m! f% m" R" W+ xthanks 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.