释义：天之险在于高不可升，地之险在于山川丘陵。王公设险以保卫国家，险的功用非常大。

The main thing in life is not to stop questioning. Curiosity has its own reason for existing.

A pure hand needs no glove to cover it.

I strongly believe that missionaries make better products. They care more. For a missionary， it's not just about the business. There has to be a business， and the business has to make sense， but that's not why you do it. You do it because you have something meaningful that motivates you.

美国是世界上最强大的国家，在可预见的未来仍将如此。