单项选择题
A.Open the crankcase immediately to check for damage
B.Apply fire fighting water through the crankcase breather
C.Allow the engine to cool before opening the crankcase
D.Assume that there is no damage to the crankshaft
单项选择题 A substance found in residual fuels which tends to cause exhaust valve corrosion and grooving, is（）
单项选择题 If the turbocharger of a four-stroke/cycle diesel engine fails to operate, which of the following statements best describes the probable effect?（）
单项选择题 The best tool to use for removing the carbon ridge at the top of an enginecylinder, prior to removing the piston, is to use（）