单项选择题
A dirty lube oil strainer can result in（）
A.crankcase B.low lube oil temperature C.excessive oil consumption D.low bearing oil pressure
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?（）
单项选择题 Proper dispersion of fuel in a diesel engine cylinder is dependent upon the （）
