不同民族之间的文化差异并非源于民族本身的生理特征差异，而是源于其历史发展的差异。

The best way to cheer yourself up is to try to cheer somebody else up.

Collaboration across borders is essential to combat deforestation and climate change.《全球森林管理》

If you're not stubborn, you'll give up on experiments too soon. And if you're not flexible, you'll pound your head against the wall and you won't see a different solution to a problem you're trying to solve.