单项选择题
A dirty fuel oil filter element can be detected by （）
A.Visual inspection of the element B.the pressure drop cross the filter C.high fuel oil tank temperature D.increase flow rate from the filter
单项选择题 The major cause of fuel pump and injection system problems is （）
单项选择题 A diesel engine should not be operated at low loads for long periods of time because（）
单项选择题 Diesel engine fuel oil contamination often results in （）
