A quarry should heal the earth even as it harvests from it.

奈奎斯特准则提供了一种图形方法来确定闭环系统的稳定性。

For beautiful eyes, look for the good in others; for beautiful lips, speak only words of kindness; and for poise, walk with the knowledge that you are never alone.

城市冰冷而空旷，没人在周围评判我。