International politics is a ruthless and dangerous business, and it is foolish to expect states to behave according to moral principles.

任何工厂中最危险的化学品不是罐子里的那些，而是自满情绪。

Small-scale farmers are the backbone of sustainable aquaculture; their knowledge is irreplaceable.

真正的科学进步不是通过简单的事实积累实现的，而是通过理论和模型的不断精炼。