单选题How does the engine adjust itself to different formulas of fuel?ABy piping in more oxygen for ethanol.BBy sensing the amount of oxygen in a car’s exhaust.CBy burning in a less-than-optimal mode.DBy stopping and checking the fuel tank.
单选题
How does the engine adjust itself to different formulas of fuel?
A
By piping in more oxygen for ethanol.
B
By sensing the amount of oxygen in a car’s exhaust.
C
By burning in a less-than-optimal mode.
D
By stopping and checking the fuel tank.
参考解析
解析：
从录音中提到的“The new technology works by “sniffing” the amount of oxygen in a car’s exhaust”，可知这项新技术通过感知汽车废气中氧的含量来进行调整。
【录音原文】
Petrol burns best with an air-to-fuel ratio of around 14:1. This means that, for every kilogram of fuel burnt, all of the oxygen in 14 kilograms of air will be consumed. Ethanol, though, requires an air-to-fuel ratio of 9:1. The new technology works by “sniffing” the amount of oxygen in a car’s exhaust. If too much or too little of the gas is sensed, it indicates that the fuel is burning in a less-than-optimal way, and thus that the air-to-fuel ratio is wrong. A signal is then sent to the engine to tweak the ratio appropriately.
从录音中提到的“The new technology works by “sniffing” the amount of oxygen in a car’s exhaust”，可知这项新技术通过感知汽车废气中氧的含量来进行调整。
【录音原文】
Petrol burns best with an air-to-fuel ratio of around 14:1. This means that, for every kilogram of fuel burnt, all of the oxygen in 14 kilograms of air will be consumed. Ethanol, though, requires an air-to-fuel ratio of 9:1. The new technology works by “sniffing” the amount of oxygen in a car’s exhaust. If too much or too little of the gas is sensed, it indicates that the fuel is burning in a less-than-optimal way, and thus that the air-to-fuel ratio is wrong. A signal is then sent to the engine to tweak the ratio appropriately.
相关考题：
In the experiment, the burning inside the bottle can___.A. equalize the air pressure inside and outsideB. make a seal in the neck of the bottleC. finish up the oxygen inside the bottleD. produce more oxygen inside the bottle
Using an inert gas system on a tanker has which advantage（s）________．A.Provides for faster loadingB.Lowers oxygen content in the tankC.Provides better fuel economyD.All of the above
How does foam extinguish an oil fire ?______.A.By cooling the oil below the ignition temperatureB.By removing the fuel souce from the fireC.By excluding the oxygen from the fireD.By increasing the weight of the oil
单选题How does foam extinguish an oil fire?（）ABy cooling the oil below the ignition temperatureBBy removing the fuel source from the fireCBy excluding the oxygen from the fireDBy increasing the weight of the oil
单选题Burning fuel with a high sulfur content in a diesel engine will （）Aincrease thermal efficiencyBcause clogging of the fuel systemCincrease the ability of the engine to start in cold weatherDproduce corrosion in the cylinder and exhaust system at low loads
单选题The burning of fuel oil in a diesel engine having a high sodium content, will cause （）Acorrosion and grooving of exhaust valvesBcorrosion and gumming of the fuel injection pumpCsalt deposits in the exhaust manifoldDslag deposits in the fuel injection equipment
单选题The consistent burning of fuel oil with a high sulfur content in a diesel engine will result in （）Aclogged fuel injection pumpsBincreased cylinder liner wearCintake valve stem corrosionDvarnish deposit on pistons
单选题Using an inert gas system on a tanker has which advantage(s)? （）AProvides for faster loadingBLowers oxygen content in the tankCProvides better fuel economyDAll of the above
单选题A practical way of checking for excessive fuel injection in one cylinder of an operating diesel engine is to （）Afeel the high pressure fuel lineBcheck the cylinder exhausts for white smoke frequentlyCcheck the cylinder exhaust temperatureDisolate each cylinder and inspect the injector
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In a diesel engine, offers the heat energy directly（）； works as working medium and changes the heat energy to mechanical energy（）Athe burning of the fuel； medium shaftBfuel spray； fresh airCfuel； fuel sprayDthe burning of the fuel； the burned gas mixture
单选题When the fuel oil is burning in the combustion chamber, it （）.Agives up large amount of heatBgives off large amount of heatCgives up large amount of steamDgives off large amount of steam
单选题Besides heat, fuel, and oxygen, which of the following is necessary for a fire to exist?（）AChain reactionBThermal actionCChemical occlusionDPyrotechnical reaction
单选题If the engine does not start on air, it may be due to （）Alow compression of the fuel pumpsBincorrect timing of fuel pumpsCthe starting air valves stuckDair-locks in fuel oil pipeline
单选题The best method of extinguishing a class A fire is to（）.Aremove oxygen from the areaBcool fuel below ignition temperatureCsmother with CO2Dsmother fire with foam
单选题What is required in addition to the heat，fuel，and oxygen of the fire triangle to have a fire?（）AElectricityBChain reactionCPressureDSmoke
单选题When the incinerator is stopped, which of the following is wrong?（）AAfter stopping supplying sludge oil, the value and pipe should be flushed by flushed by diesel oil and the incinerator continue burning for 10 minutesBClose auxiliary burner firstly and then close main burnerCAfter stopping fuel, restoring the position of main fuel supply valveDStop blower as soon as stopping supplying fuel oil
单选题The ignition quality of a fuel oil is an important operational consideration because it（）Aindicates the amount of abrasive material in the fuelBaffects the starting ability of a cold engineCdetermines the amount of fuel penetration engineDaffects the compression ratio of an operating engine
单选题Before entering a fuel tank that has been cleaned, it should be checked with an oxygen indicator and a/an（）.AOrsat apparatusBflame safety lampCHalide torchDcombustible gas indicator
单选题The efficient burning of fuel in a diesel engine is dependent upon the （）Atemperature of compressionBatomization of the fuelCpenetration of the fuelDall of the above
单选题Which of the following machinery space operations is required to be logged in the Oil Record Book?（）ABallasting or cleaning of fuel oil tanksBShifting suction of main fuel pump to reserve fuel oil tankCChanging out sprayer plates to adjust for steam demandDDaily inspection of engine room bilges
单选题While testing a cargo tank，your oxygen indicator reads 25% oxygen in the tank. You would then （）.Aenter the tank safelyBsuspect the accuracy of the readingCventilate the tankDtest for nitrogen
单选题If the engine does start on air, but combustion does not immediately begin, the cause may not be （）.Alow compressionBfailure of the fuel pump to discharge fuelCincorrect timing of fuel pumpDturning gear being still on
单选题When the load is increased on a turbocharged diesel engine, the amount of increased air supplied by the turbocharger will（）Alag behind the increased fuel supplied to the engineBenter the engine along with the increase in the fuelCenter the engine before the increased fuel supplyDleave the turbocharger as a negative pulse
单选题The main purpose of changing main engine to electronic controlled is not to（）Acontrol fuel injection time more preciselyBcontrol fuel injection rate more preciselyCmeet the environmental requirementsDmeet high engine speed requirements
单选题The ash content of a fuel oil is significant to the operating engineer because it （）Ais an indication of the amount of noncombustible material present in the oilBindicates the quantity of energy released by burning a unit amount of the fuelCis useful for determining proper atomization temperaturesDreflects the overall thermal efficiency of the fuel oil service system
单选题A viscosity regulator used for an engine is usually provided in order to （） for an engine burning heavy fuel oil.Aregulate the fuel supplyBmaintain a constant fuel viscosity at the fuel valvesCmaintain efficient coolingDalter the fuel density