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单选题
Injectors on modern engines are cooled by a combination of the intensive bore cooling in the cylinder by a combination of the intensive bore pockets and by the fuel which is re-circulated through the injector when the follower is on the （）of the cam or when the engine is stopped.
A
slope
B
base
C
top
D
bottom
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Why did Hadisiko hasten to add "his companies .also hold modern personnel management systems…… "?A． He thought Mysticism was not so good as expected.B． To show they too focused on qualifications.C． To show they hired qualified persons.D． To show the possibility of combination of the scientific management with religion.
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Each cylinder liner on the marine medium speed engines _____.A.is usually cooled by sea waterB.can be replaced when worn outC.is in direct contact with the water in the bore of the cylinderD.can t expand when heated
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此题为判断题(对，错)。
考题
第一组Older loop scavenged engines may have a single injector mounted centrally in the cylinder head. Because the exhaust valve is in the center of the cylinder head on modern uniflow scavenged engines the fuel valves (2 or 3) are arranged around the periphery of the head. The pressure at which the injector operates can be adjusted by adjusting the loading on the spring. The pressures at which the injectors operate vary depending on the engine, but can be as high as 540 bar. Some injectors have internal cooling passages in them extending into the nozzle through which cooling water is circulated. This is to prevent overheating and burning of the nozzle tip. Injectors on modern engines do not have internal cooling passages. They are cooled by a combination of the intensive bore cooling in the cylinder head being close to the valve pockets and by the fuel which is re-circulated through the injector when the follower is on the base of the cam or when the engine is stopped. As well as cooling the injector, re-circulating the fuel when the engine is stopped keeps the fuel at the correct viscosity for injection by preventing it from cooling down. Fuel injectors must be kept in good condition to maintain optimum efficiency, and to prevent conditions arising which could lead to damage within the cylinder. Injectors should be changed in line with manufacturers recommendations, overhauled and tested. Springs can weaken with repeated operation leading to the injector opening at a lower pressure than designed. The needle valve and seat can wear which together with worn nozzle holes will lead to incorrect atomization and dribbling.Modern uniflow scavenged engines have______.A.a single injector mounted in the center of the cylinder headB.several injectors mounted around the external boundary of the cylinder headC.a single injector mounted at the external boundary of the cylinder headD.several injectors mounted in the center of the cylinder head
考题
Injectors for use with heavy fuel oil must be cooled by either water or light oil to_____.A.prevent heat corrosion to internal componentsB.increase fuel delivery rate and economyC.prevent pre-ignitionD.avoid carbonization of the nozzle tips
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The writer thinks that we can't judge ______.A. buildings by the ancient standardsB. all the buildings by the ancient standardsC. all the modern buildings by the ancient standardsD. modern buildings
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Cylinders of marine diesel engines are normally cooled by ___ .A.sea waterB.fine mineral oilC.sanitary waterD.fresh water
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Modern marine diesel engines equipped with mechanical fuel injection operate on a combustion phase within the cycle which is ______.A.entirely constant pressureB.entirely constant temperatureC.a combination of constant volume and constant pressureD.a combination of constant temperature and constant pressure
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The writer thinks that_________.A.we can’t judge buildings by the ancient standards
B.we can’t judge all the buildings by the ancient standards
C.we can’t judge all the modern buildings by the ancient standards
D.we can’t judge modern buildings
考题
单选题In order to control thermal stresses, some types of modern engines use pistons with（）A
heavy wall and intensive coolingB
heavy wall and no coolingC
thin wall and no coolingD
thin wall and intensive cooling
考题
单选题In modern installations, the main engine and the standby auxiliary engines（）A
can be started at low temperature and are free from preheatingB
usually are preheated by steam before being startedC
are kept at a constant temperature and free from preheatingD
are kept at a low temperature to save energy
考题
单选题On most modern diesel engines, the main and connecting rod bearings receive their lubricating oil by （）.A
banjo feedB
splash feedC
gravity feedD
pressure feed
考题
单选题Which of the following will be the function of lubricating oil used in marine engines?（）A
to remove heat from oil cooled pistonsB
to wash away wear detritusC
to neutralize acidic productsD
all of the above
考题
单选题Each cylinder liner on the marine medium speed engines （）.A
is usually cooled by sea waterB
can be replaced when worn outC
is in direct contact with the water in the bore of the cylinderD
can t expand when heated
考题
单选题（）, so they are widely used on board ship nowadays.A
Diesel engines have more advantages in comparison with gasoline enginesB
Diesel engines have more advantages in comparison to gasoline enginesC
Gasoline engines have more advantages in comparison with diesel enginesD
Gasoline engines have more advantages in comparison to diesel engines
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单选题---Slow ahead both engines! ---Slow ahead both engines! （）!A
Both engines slow aheadB
Engine slow ahead portC
Engine slow ahead starboardD
Engine both ahead
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单选题Cylinders of marine diesel engines are normally cooled by （）.A
sea waterB
fine mineral oilC
sanitary waterD
fresh water
考题
单选题Injectors for use with heavy fuel oil must be cooled by either water or light oil to （）A
prevent heat corrosion to internal componentsB
increase fuel delivery rate and economyC
prevent pre-ignitionD
avoid carbonization of the nozzle tips
考题
单选题Refrigerant entering the compressor of a refrigeration system should be in which of the following conditions?（）A
Sub-cooled liquidB
Sub-cooled vaporC
Superheated vaporD
Liquid
考题
单选题The school uses a combination of modern and（）methods for teaching reading.A
traditionalB
oldC
ancientD
present
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单选题The crankshafts on the large modern 2-stroke crosshead engines are （）big （）makes as a single unit and so are constructed by joining together individual forgings.A
enough；toB
too；toC
such；soD
so；that
考题
单选题On engines having oil cooled pistons the lubricating oil pre-heater must be put into operation and the rate of heating so （） that the temperature of the piston cooling oil returns are 32℃ to 35℃ over a period of at least two hours.A
slowB
quickC
arrangedD
high
考题
单选题（） providing lubricating films, oil used in marine diesel engines have to remove heat from oil cooled piston.A
Except forB
BesideC
ExceptD
In addition to
考题
单选题Modern marine diesel engines using mechanical fuel injection, operate on a combustion cycle which is（）A
a combination of constant volume and constant pressureB
a combination of constant temperature and constant pressureC
entirely constant pressureD
entirely constant volume
考题
单选题Modern marine diesel engines equipped with mechanical fuel injection operate on a combustion phase within the cycle which is（）A
entirely constant pressureB
entirely constant temperatureC
a combination of constant volume and constant pressureD
a combination of constant temperature and constant pressure
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单选题In some modern large diesel engines, which of the following is used as the support for the main bearings?（）A
BedplateB
BlockC
BaseD
Sump
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单选题What is the best way to revise sentence 4 (reproduced below)?Safe but not boring, a good combination.A
(As it is now)B
Safe but not boring. A good combination.C
It’s safe but not boring, which is a good combination.D
It’s safe but not boring; therefore it was a good combination.E
Safe but not boring and a good combination.
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