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 dynamics of perception are governed by the principle of Prägnanz (good form).
真相并不总是美丽的，美丽的言辞也未必是真相。
Technology is just a tool. The real challenge is to use it wisely.