The continuing addition of large amounts of nitrogen and phosphorus to aquatic ecosystems may exceed planetary boundaries and create a "tipping point" in which
A) nitrogen and phosphorus are depleted from soils.
B) high nitrogen and phosphorus levels cause aquatic ecosystems to change in ways difficult to reverse and that are damaging to human food production.
C) these ecosystems produce far more human food than ever before.
D) water is lost from these systems, and they become deserts.
B
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What marine resource has been rendered uneconomical due to the cost of excavation?
A) Magnesium compounds B) Manganese nodules C) Sand and gravel D) Salt
Pollution concentration is
A) determined solely by the quantity of emissions. B) determined solely by the wind speed. C) the quantity of a pollutant found within a specific volume of air. D) always higher during the day than at night.
Extratropical cyclones over large bodies of water
A) can gain both sensible heat and latent heat from the water. B) are usually weaker than if they were over land. C) lose much energy to the water. D) are called "busts." E) all of the above
List the advantages and disadvantages of using a standard rain gauge vs. weather radar to measure precipitation
What will be an ideal response?