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单选题
In the four-stroke engine, it takes （） to make one power stroke.
A
one propulsion
B
two propulsions
C
two revolutions
D
one revolution
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单选题（）uses one or two high pressure pumps for all the cylinders with one more standby, while（）have a separate high-pressure pump for each cylinder.A
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考题
单选题The term （） refers to one complete sequence of operations required to produce power in an engine.A
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strokeC
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a two-stroke engine can’t work without a blower
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单选题In a four-stroke engines the camshaft rotates at （）.A
half the engine rotational speedB
twice the engine rotational speedC
the engine rotational speedD
four times the engine rotational speed
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