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Which of the listed effects represents the purpose of heat treating steel?（）
A . Develop ductility
B . Improve machining qualities
C . Relieves stresses
D . All of the above
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The heated feed-water entering any flash chamber of a flash-type evaporator will（）
A . vaporize, with the un-flashed water remaining at the temperature at which it entered the flash chamber
B . vaporize, with the un-flashed eater equalizing to the saturation conditions existing in the f lash chamber
C . vaporize, with the remaining water a t a temperature greater than it entered the flash chamber
D . boil, allowing steam bubbles to rise through the brine at the bottom of the flash chamber
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In a refrigeration system, the refrigerant absorbs the latent heat of vaporization in the（）.
A . compressor
B . condenser
C . receiver
D . evaporator
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The treatment of the fuel oils involves storage, heating, filtering and（）
A . centrifuging
B . pressurizing
C . atomization
D . igniting
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The sensible heat of air is dependent upon the （）.
A . dry bulb temperature
B . wet bulb temperature
C . saturation temperature
D . water vapor superheat
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The rate of expansion of heated fuel oil varies with the （）.
A . conductivity
B . viscosity
C . volume
D . specific gravity
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The steam boiler is part of a closed loop steam, whereby, after the energy of the steam is used up and it becomes water again, （） is collected and returned back to the boiler for heating up again to steam.
A . the former
B . the first
C . the latter
D . the last
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Which of the processes listed consumes the greatest amount of power while producing the greatest amount of heat?（）
A . Overcoming sliding friction
B . Overcoming rolling friction
C . Overcoming fluid friction
D . Overcoming oil wedge frictio
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The heat required to change a substance from a solid to a liquid while at its freezing temperature, is known as the latent heat of （）.
A . fusion
B . vaporization
C . condensation
D . sublimatio
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Heat causes the（）of gas.
A . growth
B . increase
C . expansion
D . extensio
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When bilge water is heated in a holding tank, which one of the following statements is not accurate?（）
A . The high temperature facilitates primary gravity separation
B . Most of the oil and organic solvents are raised to the top layer
C . The high the temperature is, the more the top oil will be collected
D . The high temperature has little use on the separation of emulsified oil
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In （）, hot diesel engine jacket water passes over the stack and heats the sea water passing through the tubes.
A . a flash generator
B . a flash evaporator
C . a vacuum boiling evaporator
D . a boiler
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The amount of heat released by steam when it changes to water at the same temperature is called（）.
A . latent heat of condensation
B . latent heat of vaporization
C . latent heat of saturation
D . sensible heat of condensatio
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The latent heat of evaporation is dissipated in the （） in a compression refrigeration system.
A . evaporator
B . condenser
C . expansion valve
D . compressor
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A condenser is a vessel in which（） is deprived of its latent heat of vaporization and so changed to its liquid state.
A . sea water
B . fresh water
C . vapour
D . ga
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The general purpose of a heat exchanger is to （）.
A . eliminate hot air from the condenser
B . maintain steady pressure in a system
C . heat, or cool one fluid by means of another fluid
D . reduce the engine room temperature in tropical climate
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To avoid impingement attack, care must be taken with the water （） through the tubes of the heat exchangers.
A . temperature
B . velocity
C . density
D . viscosity
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Too much excess air is （）because the heat generated is being lost through the exhaust trunking instead of being made used of in heating the water to produce steam.
A . not good
B . good
C . better
D . the best
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The movement of heat within a fluid, caused by the application of thermal energy, is called （）.
A . radiation
B . conduction
C . convection
D . condo-radiatio
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The spreading of fire as a result of heat being carried through a vessels ventilation system, is an example of heat transfer by （）.
A . conduction
B . convection
C . radiation
D . windage
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The rate of heat transfer in a water-tube auxiliary boiler can be increased by （）.
A . operating the boiler at less than normal water level
B . installing fins on the firesides of water-tubes
C . increasing the amount of excess air to the burners
D . treating the boiler water with chemical oxygen scavenger
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The earth ___the necessary amount of heat and light from the sun（）
A．supplies
B．receives
C．provides
D．requires
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______ the heat to a simmer and continue to cook for another 8—10 minutes or until most of the water has evaporated.
A．Turn off
B．Turn over
C．Turn down
D．Turn up
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The argument remained heated ______ there are necessary conditions of existence such as water on the Moon.
A、that
B、whether
C、if
D、about which
