The concept of legal validity is crucial for understanding the nature of law.
记着，希望是件好东西，没准儿是件最好的东西，而且从没有一样好东西会消逝！
I never looked at the consequences of missing a big shot... when you think about the consequences you always think of a negative result.
挑战是伪装的机会；勇敢地拥抱它们。
"New York is a city of reflections. The glass, the metal, the water - everything reflects."
书籍是反映我们梦想的镜子。
To do mathematics is to explore an infinite landscape of ideas.