单项选择题
In a closed cooling system for a turbocharged, four-stroke/cycle diesel engine, fluctuating water pressure can be caused by （）
A.improper venting of the cooling system B.carrying the expansion tank water level too high C.a totally clogged impeller in the cooling water pump D.an incorrectly set cooling system temperature control
单项选择题 A dirty lube oil strainer can result in（）
单项选择题 Differential needle valves used in fuel injectors are directly closed by（）
单项选择题 In a closed cooling water system, which of the problems can cause the water pressure to fluctuate?（）
