The key to comedy is timing, and the key to timing is patience.

水产养殖企业要敢于走出去，参与国际竞争。

The only limit is the one you set for yourself.

The most important thing is that we develop an interest in the world and take joy in our fellow human beings.

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。