rapids

n. 急流, 湍流

例句与用法：

The boat shot the rapids.

那条船穿过急流。

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

They fell into the seething waters of the rapids.

他们跌进了汹涌的急流中。