浮力

例句：

1. 1. The boat is too heavy forthe current to lift it.
   这艘船太重了，无法被水流抬起。
2. 2. The balloonrises due to the buoyant force of air.
   气球因空气的浮力而上升。
3. 3. The weight of theobject is balanced by its buoyant force.
   物体的重量由其浮力平衡。