The joy of discovery in mathematics is like solving a puzzle that the universe has left for us.

Taught from infancy that beauty is woman's sceptre, the mind shapes itself to the body, and roaming round its gilt cage, only seeks to adorn its prison.

Assume anyone asking for your account information for any reason is guilty of scamming you， unless proven innocent. The way to prove innocence is to call them back， or login to your account using numbers or a website that you provide， not them. Don’t release any identifying information while they are contacting you via phone， message or email. You must control the channel.

出自北齐·颜之推《颜氏家训·勉学》。不管是愚人还是聪明人，总想自己见多识广，但不肯读书，这就等于想吃饱饭却懒得做饭，想穿暖却懒得缝制衣服。

墨翟我上没有侍奉国君的差事，下没有耕田种地的艰难，我怎么敢放弃读书呢？