real fluid

例句：

1. 1.The real fluid in the system is responsible for the flow of heat.
   系统中的真实流体负责热量的流动。
2. 2. The real fluid in the engine is oil.
   发动机中的真流体是油。
3. 3. The real fluid in the container is water.
   容器中的真流体是水。