gravity drop hammer

例句：

1. 1.The gravity drop hammer is used to break down large rocks.
   重力锤用于破碎大岩石。
2. 2.The engineers used the gravity drop hammer to level the ground.
   工程师们使用重力锤来平整地面。
3. 3. The gravity drop hammer was a revolutionary tool in the construction industry.
   重力锤是建筑行业的一项革命性工具。