地球是一个动态的物体，其表面在不断变化。

The theory of Communism may be summed up in one sentence: Abolish all private property.

If you do what you’ve always done, you’ll get what you’ve always gotten.

投资更清洁的煤炭技术是对能源未来的投资。

Architecture is about people and the land. It is about creating spaces that serve the community and respect the environment.

系统的稳定性取决于开环传递函数在复平面上的行为。