All diesel engines are classified as ______．A.Four cycleB.Compression ignitionC.Vacuum ignitionD.External combustion
All diesel engines are classified as ______．
A.Four cycle
B.Compression ignition
C.Vacuum ignition
D.External combustion
相关考题：
Proper lubrication of the main bearings is more easily obtained in a single acting, four-stroke/cycle diesel engine than in a tow-stroke/cycle diesel engine because________.A.The direction of pressure on the journal in four-stroke engine is continuouslyB.positive feed lubricators are installed on all bearings of four-stroke engine, whereas as a splash feed system is used on tow-stroke engineC.four-stroke engines usually utilize a heavier grade of oil than tow-stroke enginesD.Low-stroke engines usually consume less lube oil than four-stroke engines
The challenge that newspapers faced from the website is （ ）[A] the small text-ads that appear alongside search engines[B] the localization of website and more elaborate service[C] the display advertisements[D] the classified advertisements
Vessels required to be equipped with an approved backfire flame arrester are ______．A.Those with diesel enginesB.All those with gasoline enginesC.Those with large engines onlyD.None of the above
单选题Compared to four-stroke/cycle engines, two-stroke/cycle diesel engines have the disadvantage of （）Aless even torqueBhigher cylinder head temperaturesCfewer power strokes per revolutionDgreater weight/size requirements
单选题In order to keep excess oil from the intake ports in two-stroke/cycle diesel engines, （）Awide compression rings are usedBoil rings are located above the pistonCchromium plating is used on all piston ringsDoil rings are located near the bottom of the piston skirt
单选题Scuffed cylinder liner wearing surfaces in a diesel engines can result from （）Achromium plating piston ringsBknurling the piston skirtCextended maximum power operationDapplying load to a cold diesel engine
单选题Diesel engines are considered safer than gasoline engines because（）.Athey are more heavily builtBthe fuel used is less volatileCthey can be easily reversedDthey operate at a lower speed
单选题（）, so they are widely used on board ship nowadays.ADiesel engines have more advantages in comparison with gasoline enginesBDiesel engines have more advantages in comparison to gasoline enginesCGasoline engines have more advantages in comparison with diesel enginesDGasoline engines have more advantages in comparison to diesel engines
单选题Proper lubrication of the main bearings is more easily obtained in a single acting, four-stroke/cycle diesel engine than in a tow-stroke/cycle diesel engine because（）.AThe direction of pressure on the journal in four-stroke engine is continuouslyBpositive feed lubricators are installed on all bearings of four-stroke engine, whereas as a splash feed system is used on tow-stroke engineCfour-stroke engines usually utilize a heavier grade of oil than tow-stroke enginesDLow-stroke engines usually consume less lube oil than four-stroke engines
单选题In conventional systems, the injection pressure（）, while it’s（）in common rail diesel engines.Afluctuates with the engine speed to some extent, independent of the engine speedBkeeps constant at all engine speed, dependent on the engine speed to some extentCkeeps constant at all engine speed, independent of the engine speedDis decided by the engine speed, constant at all engine speed
单选题The cetane number rates fuels for diesel engines according to its （）Aantiknock characteristicsBignition qualitiesCrates of vaporizationDviscosity
单选题Exhaust pipes for separate diesel engines can be combined only when （）Aspace limitations prevent separately run pipesBthe engines are small auxiliary unitsCthey are arranged to prevent gas backflow to each engineDa waste heat boiler is installed
单选题The separation of impurities and water from （） is essential for good combustion of diesel engines.Alube oilBfuel oilCturbine oilDgrease
单选题Some diesel engines are supercharged with a （）Aslam chargerBturbochargerCfuel atomizerDfuel injector
单选题（） the engines, the diesel engine is（） used engine on board.ABetween；more commonlyBAmong；the most commonlyCBetween；not more commonlyDAmong；not the most commonly
单选题An efficient seal between the cylinder block and cylinder heads on many diesel engines is obtained with（）Agraphite packingBsealing compoundClubricating oilDgaskets
单选题Which of the following statements is correct for the design and installation of diesel engine cooling water systems?（）AAn alarm device with audible and visible signals is required for all cooling water systemsBPropulsion engines with bores over 200 mm are to be fitted with cooling water jacketsCEach totally enclosed cooling system shall be provided with a suitable head tankDDrain cocks are to be provided at the lowest points of all cylinder water jackets
单选题All diesel engines are classified as（）.Afour cycleBcompression ignitionCvacuum ignitionDexternal combustion
单选题The main operating characteristic of diesel engines which distinguishes them from other internal combustion engines is the （）Amethod of supplying airBcooling systemCmethod of igniting fuelDvalve operating mechanism
单选题Some diesel engines are fitted with a thermometer in the cooling water outlet from each cylinderIf the cooling water temperature from all cylinders begins to rise above normal, you should suspect （）Aincrease blow-by in all cylindersBincomplete combustion in all cylinderCoverloading in all cylindersDinsufficient fuel delivery to all cylinders
单选题Most large, low-speed, main propulsion diesel engines use duplex lube oil strainer to （）Adecrease the time required between cleaningsBremoves all large and small foreign objectsCensure a positive flow of oil at all timesDensure that all lube oil has been treated twice
单选题Diesel engines obtain combustion air through turbo chargers，blowers，or（）.Aair startersBcarburetorsCnatural aspirationDair receivers