The most destructive form of ocean fishing to habitat is:

The most problematic greenhouse gas produced from most landfills is          

Macronutrients _____.

Aeration tanks are used in wastewater treatment plants to reduce _____ because of the high              .

For compound C,  17 mg/kg probably represents         .

A chronic exposure is:

The most important organ in clearing toxicants from the body is the _____which makes them           so they can be removed from the body.

Overexploitation of fish in the sea causes a phenomenon called_____ .

A septic system is_____ .

A key characteristic of aquatic dead zones is __________.