理解的改进有两个目的：首先，我们自己的知识增长；其次，使我们能够将知识传授给他人。
The improvement of understanding is for two ends: first, our own increase of knowledge; secondly, to enable us to deliver that knowledge to others.
Water runs dry but hearts never do
The most dangerous chemical in any plant isn't the one in the vats - it's complacency.
Writing is a way of making the invisible visible.