steam navvy

例句：

1. 1. The steam engine is the heart of the factory.
   蒸汽机是工厂的核心。
2. 2. The hot air rises and cools down to form steam.
   热空气上升冷却形成蒸汽。
3. 3.Steam is a common way to heat water for cooking.
   蒸汽是一种常见的加热水用于烹饪的方式。