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.

你把桃子投于我，我把李子回赠与你。桃子和李子价值相当，表明我本人是知恩图报的，也有互相赠送，礼尚往来的意思。

The future of drones lies in their ability to integrate with AI and big data.

爱自己是终身浪漫的开始。

艺术作品是永恒的碎片。