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單項選擇題

In a turbocharged four-stroke/cycle diesel engine, the exhaust valve remains open until after top dead center and the intake valve opens before top dead center to().

A.produce a scavenging effect in the combustion space
B.equalize cylinder and exhaust manifold pressures
C.alleviate the difference in valve size between the intake and exhaust
D.flush out condensate that collects after each compression stroke

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