单项选择题
In a closed cooling water system, which of the problems can cause the water pressure to fluctuate?（）
A.An open vent in the cooling system
B.A fouled sea chest
C.A restricted water passage in the engine
D.Air entrained in the cooling water
单项选择题 Proper dispersion of fuel in a diesel engine cylinder is dependent upon the （）
单项选择题 A change in engine speed is required before a governor is able to make a corrective movement of fuel rackThis aspect of governing is commonly expressed as a percent and is known as （）
单项选择题 Exhaust pyrometer readings provide an indication of the （）