Rob2233 发表于 2017-2-23 21:45 ' j: |( A. O6 E9 A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,! `. @+ W. \8 s3 {( _! {$ e9 }4 ^
这应该是比 ...
4 n8 x8 ^" O+ ethanks 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.