The purpose of the moderator in a reactor is to
A. separate the nuclear fuel from the spent products of fission.
B. provide cooling for the control rods.
C. reduce the number of neutrons available for the chain reaction.
D. slow neutrons down so that they will be more likely to initiate fission reactions.
Answer: D
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A rock is thrown straight up and reaches a maximum height. Which of the following describes the motion at the maximum height?
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