理解布莱克-斯科尔斯模型的关键在于认识到它是基于风险中性世界的概念，在这个世界中投资者对风险漠不关心。
The strong man is strongest when alone.
Loneliness is the human condition, and no amount of technology can change that.
面包师的手是他们最有价值的工具，由经验和直觉引导。
The great powers are always searching for opportunities to gain power at the expense of their rivals, and they will use force if they believe it will bring them strategic advantage.