The calm, shallow waters of coastal estuaries are easily polluted by nutrient-rich sewage. ████ ███████ ██████ ██████ █████████████ ██ █ ███████ █████ ████████████ ███ ████████ ██████ ██ █████ █████████ ███████ █ ████ ████ ██████ ███ ██████████████ ████ ███ █████ ██ █████ ███████ ███████ ████ ██ ███ ████ ██ ███ ████████
Nutrient-rich sewage can pollute and overnutrify estuary waters.
Overnutrified estuary waters cause algae to proliferate.
Abundant algae can be a food source for microorganisms that are toxic to fish.
These microorganisms kill most fish in the estuary.
Abundant algae in an estuary can cause most fish in the estuary to die.
Overnutrified estuary waters can cause most fish in the estuary to die.
Nutrient-rich sewage pollution can cause most fish in an estuary to die.
Which one of the following ███ ██ ████████ ████████ ████ ███ ███████████ ██████
Fish in an ███████ ████ ███ ████ ████████ ██ ██████ ███ █████████ ████ ██████ ██ ███ ████ █████████ ████ ███ ████ ██ ██ ███████ ████ ███ ████ ████████ ██ ████ █████ ████
In estuary waters ████ ███████ ████████ ██████ ██████████████ ████ ███ █████ ██ ████ █████████ ████ ███████ ████ █████ █████ ██ ███████████████
Nutrients and other ██████████ ██ ██████ ██ ███ ████ ████ ██ ███████ █████████ ██ ███ ███ █████ ████ ███████ ███ █████████ █████████████ ██ █████ ███████████████
Algae will not ███████████ ██ ███████ █████████ ████ ███ ███ ████████ ██ █████████████ ███████
Overnutrifying estuary waters ██ ██████ ███ ██████ ██ ███ █████ ██ ████ ██ ███ ████ ██ ███ ████████