Rob2233 发表于 2017-2-23 21:45 / A3 G) `& Q2 g3 e' ]- G9 U% Z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,, c9 r) M# u* O- ]) e+ T/ I
这应该是比 ...
) }/ J" Z5 c! f0 s+ X) v* Zthanks 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.