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

The history of mathematics is a history of human thought and progress.

最深刻的真理往往是我們最害怕的那些。

The most important political development of the modern era is the rise of the modern state.

成功是一段旅程，而不是終點。

變化不僅僅是生活的必要——它就是生活。

Writing is a journey into the unknown, a constant search for meaning in the chaos of existence.