单选题During working, when the piston is near the （）, the air ignites the fine spray of fuel.ATDCBDTCCBDCDBCD
单选题
During working, when the piston is near the （）, the air ignites the fine spray of fuel.
A
TDC
B
DTC
C
BDC
D
BCD
参考解析
解析：
暂无解析
相关考题：
Shipping society approved buoyant work vests are considered to be items of safety equipment and may be worn by members of the crew ______．A.in lieu of life preservers during fire drillsB.in lieu of life preservers during boat drillsC.in lieu of life preservers during an actual emergencyD.when carrying out duties near a weather deck's edge
Advection fog is most commonly caused by ______.A.air being warmed above the dew pointB.saturation of cold air by rainC.a rapid cooling of the air near the surface of the Earth at nightD.warm moist air being blown over a colder surface
单选题The fresh air coming in through the inner air ports, is compressed by（） to a higher pressure.Athe cylinder headBthe cross-headCthe moving pistonDthe stationary piston
单选题During working of an air compressor, （） should be drained.Aoil sumpBoil separatorCoutlet pipeDinlet pipe
单选题Cross scavenging requires the fitting of （） to prevent air or exhaust gas escape when the piston is at the top of the stroke.Aa exhaust valveBa piston skirtCa piston crownDan air suction valve
单选题The diameter of a piston is usually less at the crown than at the skirt, in order to （）.Afacilitate the installation of piston ringsBallow for the expansion of the piston during operationCprevent crankcase vapors from entering the combustion chamberDreduce wearing of the upper cylinder liner
单选题When an air started, four-stroke/cycle diesel engine is being cranked, the starting air is admitted to each cylinder during what would normally be the（）Aintake strokeBcompression strokeCpower strokeDexhaust stroke
单选题In context, which of the following is the best revision of sentence 5?ABranson is a tourist town, like those near ski or beach retorts: each year, hundreds of thousands of travelers visit during the months when its shows are in season.BBranson is a tourist town like ski and beach restore; it is visited by hundreds of thousands of people every year during the months when its shows ere in season.CLike the ones near ski and beach resorts, Branson is a tourist town, visited by hundreds of thousands of seasonal travelers during the months when their shows are in it.DVisited by hundreds of thousands of travelers during the months when its shows are in season, every year Branson is like a tourist town near beach or ski resorts.EBranson is a tourist town: hundreds of thousands of travelers like those who visit ski or beach resorts visit Branson during the months each year when its shows are in season.
单选题The burning of the fuel adds more heat to the air charge, causing it to expand and force the engine piston to do work on the crankshaftWhat does “it” mean in this sentence?（）Athe burningBthe fuelCthe air chargeDthe engine piston
单选题When starting an engine, the compressed air enters the cylinder when the corresponding piston is in position of its（）Asuction strokeBcompression strokeCpower strokeDexhaust stroke
单选题The compressed air is admitted to each cylinder through a cam operated by starting air valve when the piston has just passed its （）.ABDCBTDCCBBDCDATDC
单选题The cylinder oil is pumped into the cylinder (via non-return valves) when the piston rings pass the lubricating orifices during （）Athe upward strokeBthe downward strokeCthe power strokeDthe suction stroke
单选题During working of an air compressor, （） should be drained.Ainter coolerBcylinderCoutlet pipeDinlet pipe
单选题Where should the tops of vents from gasoline tanks terminate?（）.AIn open airBInside cabins near the overheadCIn the machinery space near the engine air intakeDUnderwater
单选题The scavenging air ports are located at （） that they are just exposed by the upper edge of the piston when the piston is in the bottom dead center position.Aso a heightBsuch a heightCso highDsuch high
单选题The starting air entering the cylinder begins when the piston（）Ahas nearly come to the TDCBhas just past the TDCChas nearly come to the BDCDhas just past the BDC
单选题Which of the following conditions can cause below normal air pressure in the intake manifold of a turbocharged diesel engine?（）AExcessive piston blow-by to the manifoldBInsufficient cooling water flowCAccumulated water in the air boxesDClogged air intake filters
单选题Directional intake ports in diesel engines are used to （）.Areduce air charge turbulenceBinduce air swirlCdeflect hot combustion gas away from the valvesDoppose the effects of piston induced squish
单选题Long hair should always be covered by（）when working with or near moving machinery.Aa helmentBsafety capCan ear plugDface mask
单选题During which of the listed piston stroke of a four-stroke/cycle diesel engine, is the piston moving downward?（）AIntake strokeBCompression strokeCExhaust strokeDPumping stroke
单选题What should you do when you need to answer a phone call during a performance?ACall back after the performance.BAnswer it near the exit door.CTalk outside the door.DSpeak in a low voice.
单选题When the starting air valve closes on one cylinder, another starting air valve has （） opened on another cylinder whose piston has just commenced its downward stroke.AjustBnearlyCmerelyDalready
单选题Broken piston rings manifest themselves during the scavenge port inspection by（）ALack of elastic tension, when the rings are pressed into the groove by means of a stickBBlackish appearanceCFractured rings and missing ringsDall off the above
单选题Coast Guard approved buoyant work vests（）.Amay be substituted for 10 percent of the required life preserversBshould be stowed adjacent to lifeboats and emergency stationsCmay be used by boat crews and line handlers during lifeboat drillsDshould be used when carrying out duties near a weather deck's edge
单选题In slow speed two-stroke engines,（）the fresh air entering begins when and stops as（）Athe inlet port is opened by the up coming piston； the port is closed by the down goingBthe inlet valve is opened by the down going piston；the inlet valve is closedCthe inlet port is opened by the down going piston；the port is closed by the up comingDthe inlet valve is opened
单选题During working, when the piston is near the （）, the air ignites the fine spray of fuel.ATDCBDTCCBDCDBCD
单选题According to the passage, which of the following will present the most difficult challenge for humans attempting interstellar space travel?AAchieving velocities near the speed of lightBWithstanding the acceleration necessary for traversing interstellar distancesCMaintaining clean air and water on a journey that could last centuriesDAccommodating the effects of relativistic time dilationEEnabling the humans on board to survive during the journey