Self-study
The calm, shallow waters of coastal estuaries are easily polluted by nutrient-rich sewage. ████ ███████ ██████ ██████ █████████████ ██ █ ███████ █████ ████████████ ███ ████████ ██████ ██ █████ █████████ ███████ █ ████ ████ ██████ ███ ██████████████ ████ ███ █████ ██ █████ ███████ ███████ ████ ██ ███ ████ ██ ███ ████████
Summary
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.
Very Strongly Supported Conclusions
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.
6.
Which one of the following ███ ██ ████████ ████████ ████ ███ ███████████ ██████
a
Fish in an ███████ ████ ███ ████ ████████ ██ ██████ ███ █████████ ████ ██████ ██ ███ ████ █████████ ████ ███ ████ ██ ██ ███████ ████ ███ ████ ████████ ██ ████ █████ ████
Unsupported. Nutrient-rich sewage can kill most fish in an estuary, but we don’t know that it’s more likely to than other forms of pollution.
b
In estuary waters ████ ███████ ████████ ██████ ██████████████ ████ ███ █████ ██ ████ █████████ ████ ███████ ████ █████ █████ ██ ███████████████
Unsupported. Abundant algae can be a food source for toxic microorganisms, but we don’t know that it causes toxic microorganisms to reproduce more quickly than other types of microorganisms.
c
Nutrients and other ██████████ ██ ██████ ██ ███ ████ ████ ██ ███████ █████████ ██ ███ ███ █████ ████ ███████ ███ █████████ █████████████ ██ █████ ███████████████
Unsupported. Nutrient-rich sewage can harm fish in estuaries by causing algae to grow, which feeds toxic microorganisms. But it might harm fish in other ways too.
d
Algae will not ███████████ ██ ███████ █████████ ████ ███ ███ ████████ ██ █████████████ ███████
Unsupported. Overnutrified waters do cause algae to proliferate, but it might proliferate in other conditions too.
e
Overnutrifying estuary waters ██ ██████ ███ ██████ ██ ███ █████ ██ ████ ██ ███ ████ ██ ███ ████████
Very strongly supported. Overnutrified estuary waters cause algae to proliferate, which can then feed toxic microorganisms that kill most fish in the estuary. So, nutrient-rich sewage pollution can cause the death of most fish in an estuary.