The time needed for a typical atom in an oceanic plate to complete a plate-tectonic cycle is ________ years.
A. about 10 million
B. about a million
C. about a hundred thousand
D. less than 500
E. in excess of 250 million
Answer: E
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The greatest surface warming is projected for which of the following regions during the next 100 years?
A. polar regions B. tropics C. middle latitudes D. equator
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A) innate immune cells. B) helper T cells. C) memory cells. D) killer T cells.
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A) refusal to teach other customs in schools. B) refusal to share other customs in religious ceremonies. C) inability to set up telephone service. D) limited connections due to topographic, linguistic or ethnic barriers. E) military confrontation.