色多多在线观看播放-色多多在线观看高清免费-色多多在线观看视频-色多多在线看-欧美aaaaa性bbbbb小妇-欧美aaaav免费大片

A mathematical truth is universal and eternal.

The best books are the ones that children want to read again and again.

Life is too short to waste on things that don't matter.

The Langlands program is a vision of how mathematics could be unified.

True happiness arises, in the first place, from the enjoyment of one's self, and in the next, from the friendship and conversation of a few select companions.

海洋的恩賜是一種特權，而不是一種權利。