law of convection

例句：

1. 1. The hot air rises and the cold air descends, causing convection.
   热空气上升，冷空气下降，导致对流。
2. 2. Convection currents can carry heat from one area to another.
   对流电流可以从一个区域将热量传递到另一个区域。
3. 3.In a greenhouse, plants are grown in a controlled environment with convection heating.
   在温室中，植物是在受控环境中生长的，使用对流加热。