网友您好， 请在下方输入框内输入要搜索的题目：
题目内容
（请给出正确答案）
单选题
The air reservoirs must have （） fitted to prevent rupture in the event of fire.
A
high pressure alarm
B
fire alarm
C
extinguishers
D
fusible plugs
参考答案
参考解析
解析：
暂无解析
更多 “单选题The air reservoirs must have （） fitted to prevent rupture in the event of fire.A high pressure alarmB fire alarmC extinguishersD fusible plugs” 相关考题
考题
Fuel droplets injected into a diesel engine cylinder must have adequate penetration to ____.A.prolong the ignition delay periodB.ensure the beginning of fuel injectionC.thoroughly utilize the air chargeD.allow controlled fuel combustion
考题
Which of the following reasons represents why the designed compression ratio of a gasoline engine is lower than that of a diesel engine?A.compression must be low for effective spark ignitionB.compression must be low for required horsepower and torque generationC.compression must be low to prevent pre-ignitionD.compression must be low to have effective pre-ignition
考题
According to the passage，what is one disadvantage of skyscrapers that have mirrored walls?A. The exterior surrounding air is heated。B. The windows must be cleaned daily.C. Construction time is increased.D. Extra air-conditioning equipment is needed.
考题
Motor-propelled lifeboats are required to be fitted with which of the following?______.A.Compartments for the storage of canned drinking waterB.Ballast tanks to prevent the boat from capsizingC.An air starter on the diesel engineD.Auxiliary mechanical propulsion ( Fleming gear )
考题
According to SOLAS the breathing air apparatus that must be onboard shall have sufficient capacity for how many minutes of operation?____.A.20B.30C.45D.60
考题
US and allied officials have said they have seen no credible evidence of civilian casualties（伤亡）from the air campaign,and they say that precision weapons are used in the strikes in an effort to()being hurt．A． prevent civilians onB．prevent civilians fromC． Prevent civilians toD．Prevent civilians in
考题
When adding oil to a refrigeration system, precautions must be taken to ensure thatA.the compressor suction pressure is not too highB.all air is purged from the pump and charging fittingsC.the high pressure cutout switch is held open to prevent accidental startingD.the condenser is completely shutdown first
考题
第二组Under normal operation, some lubrication oil mist may be discharged from the air compressor to the air start system. This oil may be from excess compressor cylinder lubrication, from faulty oil scraper rings, or may even be suspended oil vapor contaminating the engine room atmosphere and drawn in at the compressor suction. Oil discharge is kept to a minimum by draining the after cooler, air receiver and starting system. If small quantities of lubrication oil do get passed into the starting air system, they will deposit as thin moist film over internal pipe surfaces but are not readily combustible. If a cylinder non-return valve leak while the engine is in operation, some hot gas, possibly with unburned fuel and cylinder lubrication oil, may be blown through the valve to the adjacent air manifold. With further heating from the leaky valve, this, together with the already deposited oil film, will carbonize and form. incandescent carbon. If starting air is applied to the system while still hot, the high pressure air coming into contact with the burning carbon may cause an explosion. Such an explosion will cause a flame to pass back through the air start pipe system, evaporating the deposited oil film and igniting it in the presence of air. Very high velocities and shockwaves are generated which may rupture pipes and fittings.Alternatively, if excessive oil has entered the air start system, a mixture of air and oil droplets may be discharged through the open cylinder non-return valve during starting. This spray may ignite due to high temperatures in the cylinder, causing a flame through the still open valve to the air manifold.To prevent an explosion, air start valves must be correctly maintained and lubricated to ensure correct timing and free movement with positive closing. Oil in the system must be kept to a minimum, pipe lines must be drained and cleaned internally when necessary and oil discharge from air compressors must be kept to a minimum by good maintenance.The passage is mainly aboutA.crankcase explosionB.scavenge box fireC.starting air pipeD.the danger of explosion in the starting air system
考题
A safe fuel system must ______.A.prevent engine overheatingB.have proper air/gasoline fuel mixture ratioC.be liquid- and vapor-tightD.supply sufficient air to the intake manifold
考题
Which statement about pneumatic chipping tools is TRUE ________．A.The operator must wear safety goggles or glassesB.The equipment must be grounded to prevent shock hazardC.The chipping mechanism is made of a non-sparking material that is safe to use near explosive atmospheresD.The needles of the needle-type chipping gun must be replaced when they have been blunted more than 1/2 of their diameter
考题
The Company security administrator wants to prevent DHCP spoofing. Which statement is true about DHCP spoofing operation？（）A、 DHCP spoofing and SPAN cannot be used on the same port of a switch.B、 To prevent a DHCP spoofing， the DHCP server must create a static ARP entry that cannot be updated by a dynamic ARP packet.C、 To prevent a DHCP spoofing， the switch must have DHCP server services disabled and a static entry pointing towards the DHCP server.D、 DHCP spoofing can be prevented by placing all unused ports in an unused VLAN.E、 None of the other alternatives apply.
考题
单选题Where tanks are arranged for either oil or ballast, （） must be fitted in the pipeline.A
a change-over chestB
a head tankC
a emergency bilge pumpD
an air cooler
考题
单选题Condensate must be drained periodically from the air compressor receivers to prevent （）.A
second stage cylinder lockupB
oil sump contaminationC
faulty operation of pneumatic valvesD
corrosion of air receiver baffles
考题
单选题When adding oil to a refrigeration system, precautions must be taken to ensure that （）.A
the compressor suction pressure is not too highB
all air is purged from the pump and charging fittingsC
the high pressure cutout switch is held open to prevent accidental startingD
the condenser is completely shutdown first
考题
单选题Air reservoirs are designed, built and tested similarly to （）.A
boiler drumsB
hot wellsC
condensersD
evaporators
考题
单选题Which of the following methods is used to prevent throttling of compressed air through the diesel engine air starting valves?（）A
Holding the valve open for a long periodB
Increasing the starting air pressure usedC
Opening the stating air valve quicklyD
Reducing the starting air valve size
考题
单选题Preventer bars are fitted on lifeboat releasing hooks to prevent（）.A
the falls from unhooking if the releasing gear is operated accidentally while the boat is being loweredB
operation of the release lever until the boat is waterborneC
the falls from rehooking after they have been releasedD
accidental unhooking when the falls become slack
考题
单选题Most air conditioning units have （） for adjusting the ratio of recirculated fresh airCare must be taken not to reduce the fresh air so that stuffiness or smells arise.A
catch platesB
dampersC
regulating valvesD
fans
考题
单选题The compressed air is supplied by （） to the air reservoirs.A
compressorsB
forced fansC
ventilatorsD
generators
考题
单选题Which condition is necessary for a substance to burn?（）A
The temperature of the substance must be equal to or above its fire pointB
The air must contain oxygen in sufficient quantityC
The mixture of vapors with air must be within the explosive rangeD
All of the above
考题
单选题Starting air for auxiliary engines may be taken directly from the main reservoirs or through （）.A
an auxiliary reservoirB
a controlling air bottleC
an emergency air compressorD
a main air compressor
考题
单选题Which of the following reasons represents why the designed compression ratio of a gasoline engine is lower than that of a diesel engine?（）A
compression must be low for effective spark ignitionB
compression must be low for required horsepower and torque generationC
compression must be low to prevent pre-ignitionD
compression must be low to have effective pre-ignition
考题
单选题Pump up the starting air reservoirs to their maximum pressure and （）the air reservoirs and air system.A
openB
closeC
drainD
vent
考题
单选题（） or air venting arrangement is fitted to the fuel supply passage.A
An air pumpB
A compressorC
A fuel pumpD
A priming
考题
单选题In heavy marine engine the practice is to drive the engine on（）which has previously been stored in starting air reservoirs.A
electric motorB
hydraulic motorC
compressed airD
turning gear
考题
单选题Fuel droplets injected into a diesel engine cylinder must have adequate penetration to （）A
prolong the ignition delay periodB
ensure the beginning of fuel injectionC
thoroughly utilize the air chargeD
allow controlled fuel combustion
考题
单选题The air required for combustion is taken from the engine room through a filter fitted on the turbochargerThis reduces the risk for too and contamination of the combustion air（）A
high temperaturesB
low temperaturesC
wetD
dirty
热门标签
最新试卷
