Ethanol produced from bioenergy starts with ________ produced by ________
A) ammonia; anaerobic bacteria
B) hydrogen gas; wind turbines
C) methane; sewage sludge
D) CO2; burning fossil fuels
E) starch; corn and sugar cane
E
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The movement of groundwater is ________
A) upwards B) downwards C) sideways (horizontal) D) a curving path E) any direction according to the forces involved
The density of Earth's crust, mantle, and core increases moving toward Earth's center because
A) Earth's elements are distributed evenly throughout its interior. B) Early in Earth's history, it separated into layers according to density. C) Earth is plastic throughout its structure today and in the past. D) The charged particles flowing in the outer core repel the lighter elements found at Earth's surface.
Which shape most easily fosters the establishment of effective internal communications for a smaller state?
A) compact B) elongated C) fragmented D) prorupted E) prolonged
Which of the following describes the degree to which geologic processes have concentrated a mineral resource above its average concentration in Earth's crust?
A. enrichment factor B. geologic factor C. concentration level D. relative abundance E. economic potential