Rob2233 发表于 2017-2-23 21:45 8 x ~2 z r( d6 ~: 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, V( N( B: @4 u u这应该是比 ...
. P& [7 \7 Q7 r2 c0 athanks 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.