里氏替换原则是面向对象编程中的一个基本概念，它指出子类的对象应该能够替换超类的对象而不影响程序的正确性。
The Liskov Substitution Principle is a fundamental concept in object-oriented programming, stating that objects of a superclass should be replaceable with objects of a subclass without affecting the correctness of the program.
I'm not going to school just for the academics - I wanted to share ideas, to be around people who are passionate about learning.
成功不是目的地，而是你走过的路。
宽容是真正强大的人的品质。
皮革鞣制的创新不仅仅是技术问题，更是在尊重工艺的同时推动其发展。