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
A. development of lower-grade ore deposits. B. disturbance of more land area for mineral extraction. C. reclassification of some resources as reserves. D. significant rapid increases in total world metal resources.
Hso4- + h2o ? so42- + h3o+
What will be an ideal response?
True or False: Earthquake body wave records allow scientists to construct an image of Earth's interior
Indicate whether this statement is true or false.