问题：
[单选] When turning the engine with turning gear, you should keep the indicator cocks （）.
attached to the indicators。opened。closed。broke。
问题：
[单选] Which cause of the following can lead to the engine not to start on air?（）
starting air pressure too high。correct timing of starting air valves。three of the starting valves stuck。the turning gear disengaged。
问题：
[单选] Which factor of the following affects not only the fuels combustion but also the engine’s maintenance?（）
cetane number。flash point。viscosity。setting point。
问题：
[单选] Which of the following can be directly obtained by means of an indicator card?（）
power。maximum pressure in a cylinder。mean pressure in a cylinder。all of the above。
问题：
[单选] Which of the following can be obtained by means of an indicator card?（）
the peak pressure in a cylinder。the temperature of the cooling water。the fuel consumption。none of the above。
问题：
[单选] Which of the following firing order may be used for an 6 cylinder engine?（）
1-2-3-4-5-6。1-2-3-6-5-4。1-5-3-6-2-4。1-3-4-5-6-2。
问题：
[单选] Which of the following is a factor of fuel oil almost having nothing to do with the formation of combustion products?（）
setting point。ash。sulfur content。carbon residue。
问题：
[单选] Which of the following may cause that an engine doesnt run on starting air?（）
too low starting air pressure。main start valve closed。neither A nor B。A and B。
问题：
[单选] Which of the following may lead to the engine NOT to start on air?（）
starting air pressure too high。correct timing of starting air valves。three of the six starting valves stuck。the turning gear disengaged。
问题：
[单选] Which of the following may take place if the clearance of the main bearings are excessive?（）
bearing knocks。dropping of pressure of LO。noises。all the above。
