求翻译：乙草胺和镉是土壤生态系统中两类普遍存在且经常共存的外源化学污染物，它们复合污染对生态环境所造成的危害已不容忽视。是什么意思？

Acetochlor and cadmium is an exogenous chemical contaminants in the soil ecosystem, two types of widespread and often co-exist, they are combined pollution harm caused to the ecological environment can not be ignored.

b) D. amine and cadmium in soil ecosystem is pervasive and often two types of coexistence chemical pollutants from their compound pollution on the environment, the harm they cause can no longer be ignored.

The second grade grass amine and the cadmium are the extraneous source chemistry pollutant which in the soil ecosystem two kind of universal existences also coexist frequently, their compound pollution the harm which creates to the ecological environment already not allow to neglect.

Acetochlor and cadmium in soil ecosystem is coexistence of two classes is widespread and often of exogenous chemical pollutants, their combined pollution on ecological environmental hazards can no longer be ignored.