我从十五岁开始致力于学习，三十岁便能自立于社会了，四十岁对各种事理不再迷惑不解，五十岁懂得了自然界的规律，六十岁对听到的事情能领会贯通，并能辨别是非真伪，七十岁时做事能随心所欲，但又不会超出礼法的规范。

我不能让生命就此消逝无踪，重头再来。

The deepest theorems often have the simplest proofs - if you look at them from the right angle.

Technology alone won't solve hunger; it must be paired with equitable access and education.

The world is a book, and those who do not travel read only one page.

Pain is not always physical; sometimes the deepest wounds are the ones we cannot see.

系统的稳定性取决于开环传递函数在复平面上的行为。