问题：
[单选] A SECONDARY function of a waste heat boiler is to （）.
reduce engine exhaust noise。reduce engine back pressure。increase engine cycle efficiency。increase turbocharger efficiency。
问题：
[单选] An electric heater built into some smaller diesel engines is used to （）.
raise lube oil viscosity for easier starting in cold weather。increase air inlet temperature。increase compression ratio。increase jacket water temperature for easier starting in cold weather。
问题：
[单选] Camshafts are usually driven by timing gears or （）.
push rods。chain drives。rocker arms。flywheel。
问题：
[单选] The maximum pressure developed by a waste heat boiler is determined by the main engine exhaust （）.
gas composition。gas temperature。pressure。timing。
问题：
[单选] Waterside scale in a fire-tube boiler may cause （）.
increased heat transfer。fireside erosion。high steam demand。overheated tube。
问题：
[单选] With regards to a diesel engine crankcase explosion, the most violent is the（） (1) primary explosion (2) secondary explosion
(1) only。(2) only。both (1) and (2)。neither (1) or (2)。
问题：
[单选] When an auxiliary boiler is panting and emitting black smoke, you should （）.
increase the fuel oil temperature。decrease the fuel oil temperature。decrease the fuel oil supply pressure。increase the air supply。
问题：
[单选] A two-stroke diesel engine exhaust temperature will be lower than a four-stroke diesel engine of the same displacement because the （） (1) scavenging air is cooling the exhaust gases (2) exhaust cycle time is longer
(1) only。(2) only。both (1) and (2)。neither (1) nor (2)。
问题：
[单选] The camshaft on a four-stroke/cycle diesel engine provides a means to operate the （）.
fuel injectors。exhaust valves。intake valves。all of the above。
问题：
[单选] The rate of fuel injection in a diesel engine cylinder depends primarily on （）.
the size of the holes in the fuel nozzle。timing of the pump。supply pressure to the pump。shape of the combustion chamber。
