The power of mathematics comes from its ability to abstract and generalize, turning specific problems into universal truths.

If you lose or forget to bring a cable，adapter or charger，check with your hotel. Most hotels now have a drawer full of cables，adapters and chargers others have left behind，and probably have the one you are missing. You can often claim it after borrowing it.

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.

我不是商人；我就是生意本身。