Rob2233 发表于 2017-2-23 21:454 J& w! W# B# \. s/ l
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,* O/ v' @- h# y2 z! R# ]9 l/ J% y
这应该是比 ...
& `0 |0 ?% F1 T4 e \4 ]4 p' ythanks 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.