问题：
[单选] In order to increase the wearing resistance, the cylinder liner surfaces are sometimes （）.
aluminum-plated。bronze-plated。zinc-plated。chromium-plated。
问题：
[单选] In some designs the cylinder oil is timed so that the oil injects only on the （）.
piston crown。piston groove。piston skirt。piston ring belt。
问题：
[单选] In the （） pressure charging system the pulse of energy that occur as the exhaust is released from the cylinder to improve the output of the turbocharger.
constant。pulse。high。none of the above。
问题：
[单选] In the event of the cylinder starting valve leakage （） would pass into the air pipes and ignite the oil deposited.
cooling water。vapor from the boiler。starting air。hot gase。
问题：
[单选] In the four-stroke engine, it takes （） to make one power stroke.
one propulsion。two propulsions。two revolutions。one revolutio。
问题：
[单选] In the sentence “In some designs the cylinder oil is timed so that the oil injects only on the piston ring belt, the "piston ring belt" means （）.
piston crown。piston ring groove。piston skirt。piston ring area。
问题：
[单选] In the suction stroke air is induced into the cylinder （）In the compression stroke the air is compressed.
by an fuel valve。through an inlet valve。with an exhaust valve。from an outlet valve。
问题：
[单选] Increased air （） will raise scavenge efficiency and allow a greater mass of air to be compressed； more fuel may now be burned giving an increased power.
specific volume。density。viscosity。calorific value。
问题：
[单选] Increasing differential pressure of an oil filter indicates that （）
it is dirty。it is leaky。it has been renewed。all the above。
问题：
[单选] Increasing the temperature of a fuel will reduce its （）.
viscosity。pressure。resistance。setting point。
