对任何思考者来说，最大的挑战是以一种允许解决的方式表述问题。
The leather industry must evolve or risk becoming obsolete.
The essence of mathematics is not to make simple things complicated, but to make complicated things simple.
社会进步可以通过女性的社会地位来衡量。
A fool who knows he is a fool is for that very reason a wise man. The fool who thinks he is wise is the one to be called a fool.