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.

译文：识破人情冷暖，就会吓坏我们，看穿世间的事情，我们的内心就会寒心。赏析：世间的一切事就如人饮水，冷暖自知。人情淡薄，世态炎凉是人之常情，我们不可过多地为此伤透脑筋。放一颗平常心，过好自己的人生就行。

化学和物理的界面是奇迹发生的地方。

"We are all just walking each other home."

我不是老师，我是学生。

Change your life today. Don't gamble on the future, act now, without delay.