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.

If you want something you've never had, you must be willing to do something you've never done.

她就是这么说的。

The painting should be a fact, not a representation.

如果一个问题无法解决，那就扩大它的范围。

世界上最让我难以理解的就是所得税。