复数： sediments

The underground sediment of the ganges delta contains arsenic .

恒河三角洲地下沉积物中就含有这种毒物。

Sediment is deposited on a small and steep alluvial fan .

峡谷沉积物在小而陡的冲积扇上沉积了下来。

But contaminated sediment and marine organisms also seem to be involved .

然而似乎也牵涉到遭受污染的沉积物和海洋有机物。

With a half-life of 30 years , it accumulates in ocean sediment .

铯的半衰期为30年，且铯会积聚在海洋沉积物上。

Fishponds were abandoned , sediment filled reefs , and dynamite fishing was introduced .

鱼池被废弃，沉积物填充珊瑚，炸药捕鱼法被引进。