【释义】人穷的时候不能丧失道德的标准，而发达的时候也不能背弃自己做人的原则。

相对论是一种原理性理论，而非构造性理论。

The way positive reinforcement is carried out is more important than the amount.

The profession of book writing makes horse racing seem like a solid, stable business.

Loneliness is the curse of nature to those who live in groups, and solitude is the only way out of loneliness.

"Words are the voice of the heart."

供应链是电商的核心竞争力，没有之一。