In a diesel engine, when refitting piston rings you should______. I. check the ring gap at
A. I only
B. II only
C. both I and II
D. neither I nor II
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Fuel has been injected but ignition fails. The possible cause may be ______.
A. slightly leaky exhaust valve
B. increased scavenging air temperature
C. engine cylinders not scavenged sufficiently
D. too much water in the fuel oil
During the valve overlap period, the exhaust pressure of a turbocharged four-stroke/cycle
A. effective cylinder scavenging and cooling
B. constant pressure from the turbochargers
C. cooler operation of the exhaust system
D. effective constant pressure for turbocharger operation
The meat box temperature control circuit, as used in the ship service refrigeration system, is an example of ______.
A. two position control
B. single speed floating control
C. proportional(比例) control
D. reset control
不属于“十字文明”用语的是“()”。
A. 您好
B. 谢谢
C. 告辞
D. 对不起
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