Respuesta :
Answer:
Explanation:
Heavy industry, manufacturing and agriculture are three of the major causes of pollution of the Great Lakes system. The production of persistent organic pollutants (POPs) such as PCBs, DDT and dioxins, had previously been of principal concern.
Answer:
Heavy industry, manufacturing and agriculture
Explanation:
Heavy industry, manufacturing and agriculture are three of the major causes of pollution of the Great Lakes system.