If you're not improving, you're falling behind—especially in an industry as dynamic as animal husbandry.

解析：教导学生，不到他想弄明白而不得的时候，不去开导他；不到他想出来却说不出来的时候，不去启发他。

数学是给不同事物赋予相同名称的艺术。

The rise of China and other authoritarian states challenges the idea that liberal democracy is the only viable political system.

The improvement of understanding is for two ends: first, our own increase of knowledge; secondly, to enable us to deliver that knowledge to others.