first law of the mean

例句：

1. 1.The first law of thermodynamics states that energy cannot be created or destroyed.
   热力学第一定律表明能量不能被创造或销毁。
2. 2. The first law of thermodynamics is often used to describe the relationship between temperature and pressure in a system.
   热力学第一定律经常用来描述系统的温度和压力之间的关系。
3. 3. In physics, the first law of thermodynamics is fundamentally important because it describes how energy is transformed within a closed system.
   在物理学中，热力学第一定律是至关重要的，因为它描述了能量如何在封闭系统中转化。