浮石

例句：

1. 1. The buoyant stone helps the boat to stay afloat in the calm water.
   这个浮石帮助船只在平静的水面上保持漂浮。
2. 2. The floatable stone was used as a weight for the ship's anchor.
   这个可浮石被用作船锚的重量。
3. 3. The buoyant stone is placed at the bottom of the pool to prevent it from sinking.
   将浮石放在池底以防止它沉下去。