问题：
[单选] （） is sometimes used for piston cooling since leaks into the crankcase would not cause problems.
Diesel oil。Hydraulic oil。Lube oil。Mineral oil。
问题：
[单选] （） is the removal of exhaust gases by blowing in fresh air.
Gas exchange。Charging。Scavenging。Supercharging。
问题：
[单选] （） is used for cylinder and cylinder head, the salt water is used for cooling the lubricating oil, the fresh water in the coolers and the charging air in the air cooler.
The fuel oil。The lube oil。The sea water。The fresh water。
问题：
[单选] （） of an engine crankshaft can be detected by measuring deflections of crank webs for each unit of the engine.
Misalignment。Length。Strength。Stresse。
问题：
[单选] （） of the A-frames there is a strong cast iron frame called the scavenging air box.
At the top。At the bottom。In the top。In the bottom。
问题：
[单选] （） pistons have low inertia and high coefficient of thermal expansion.
Cast iron。Cast steel。Forged steel。Aluminum。
问题：
[单选] （） should not undertake any task which will interfere with the supervision duties relating to the main machinery and associated equipment.
The watch keeping personnel。The chief engineer。The person on a bunker barge。Any of the above。
问题：
[单选] （） the cylinder will contain a great weight of air and will be capable of burning a great quantity of fuel.
At the beginning of the compression stroke。At the beginning of the suction stroke。At the end of the working stroke。At the end of the exhaust stroke。
问题：
[单选] （） the supercharge pressure is, （） power an engine develops.
The higher；the more。Higher；more。Higher；little。The higher；the le。
问题：
[单选] （） is not properly set thus causing either advanced or retarded firing.
A piston。A fuel injection pump。A feed water pump。A lube oil pum。
