riverbed

名词 riverbed:

1. a channel occupied (or formerly occupied) by a river
   同义词：river bottom

1. Sediment deposited by flowing water, as in a riverbed, flood plain, or delta.
   冲积层河床、洪水淹没的平原或三角洲中的流水淤积所产生的沉积层
2. There are many pebbles on the riverbed.
   河床上有很多卵石。

riv.er.bed

n.（名词）
The area between the banks of a river ordinarily covered by water.
河床：常被水覆盖的一条河流两岸之间的区域