cooling velocity

例句：

1. 1. The engine needs to cool down before it can be used again.
   发动机需要冷却后才能再次使用。
2. 2.The temperature dropped significantly during the night, which slowed down the cooling velocity of the air.
   夜间温度显著下降，减缓了空气的冷却速度。
3. 3. The researchers found that the cooling velocity of the liquid depended on its initial temperature and the amount of heat added.
   研究人员发现，液体的冷却速度取决于其初始温度和加入的热量量。