loose stone

• 松动金刚石

loose stone的用法和样例：

例句

1. A deep, round hole worn in rock by loose stones whirling in strong rapids or waterfalls.
   锅穴，壶穴岩石上深深的圆洞，由于急流或瀑布的水涡带动疏松的石块旋转而成
2. She stepped on a loose stone and twisted her ankle.
   她踩到一块松动的石头上，扭伤了脚踝。