可持续性不仅仅是一种趋势,更是我们对下一代的责任。
这个世界是个美好的地方,值得为之奋斗。
数学的美在于它允许我们抽象出现实世界的复杂性,专注于基本原则。
The best way to ensure peace is to maintain a balance of power among the major states.
Happiness is not the absence of problems, but the ability to deal with them.