Hypoxic areas such as in the Gulf of Mexico develop when ________.
A. die-off from a large phytoplankton bloom uses up the oxygen in water
B. oxygen levels fall below 5 ppm
C. oxygen levels fall below 5 ppm, large amounts of nitrate are added into the water, and die-off from a large phytoplankton bloom uses up the oxygen in water
D. methyl-mercury is added to water
E. large amounts of nitrate are added into the water
Answer: C
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If demand forces metal prices up, all of the following can be expected except
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Which of the following are widely used technologies that are responsible for wasting enormous amounts of energy?
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Indicate whether this statement is true or false.