单项选择题
What is commonly used to create turbulence in a diesel engine combustion system?（）
A.Shape of the piston crowns B.Increasing the compression ratios C.Increasing the piston crowns D.Increasing the turbocharger gear ratio
单项选择题 What causes diesel fuel to be ignited in the cylinder of an operating diesel engine?（）
单项选择题 If a diesel engine fails to start，one of the likely causes is （）
单项选择题 Icreasing the exhaust valve tappet clearance of a diesel engine will result in the exhaust valve opening （）
