单项选择题 Which of the listed types of starting systems is often used on large, low-speed, direct reversing, main propulsion diesel engines?（）

单项选择题 In a large, low-speed diesel engine the clearance between the piston crown and cylinder head is found to be excessiveIn order to correct for this, you should（）

单项选择题 A mixture of 45%cetane and 55% alpha-methyl-naphthalene is found to have the same ignition delay as a sample of diesel oil √The sample can be described as having a/an（）