The only certainty is uncertainty.

教师必须为形成较好人类而献出一切。

最好的矿业公司不仅仅是遵守法规，他们还帮助制定法规。

Un libro es un mundo en sí mismo, un universo que se abre ante nuestros ojos.

The great and chief end, therefore, of men's uniting into commonwealths and putting themselves under government is the preservation of their property.

我只是想传播正能量。