我们的选择，而非能力，更能展现我们真正的自我。

The Liskov Substitution Principle is a fundamental concept in object-oriented programming, ensuring that derived classes can be used in place of their base classes without altering the correctness of the program.

解释：齐国是强国，利用它的强大进攻宋国，让他逞强，燕国就可以乘机打败齐国；齐国是大国，利用它的大国野心吞并宋国，增加土地，燕国就可以乘机进攻。

The secret of great fortunes without apparent cause is a crime forgotten, for it was properly done.

The study of computational complexity is not just about classifying problems; it is about understanding the nature of computation itself.