If you loan someone $20 and you never see them again. That makes it worth $20. 

Topological insulators are a prime example of how theoretical predictions can lead to experimental discoveries that reshape our understanding of the physical world.

我不是一个放弃爱情的人。

知足者常乐，追求无止境的欲望永无满足。

"The Middle East is not just a place of conflict; it's a place of deep humanity and untold stories."

"Every word we write is a step towards understanding ourselves and the world around us."