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单选题
Which of the statements listed concerning heat transfer is correct?（）
A
Heat is always transferred at a constant rate
B
Heat transfer rate increases as temperature difference increases
C
The rate of heat transfer is not affected by temperature difference
D
The high temperature region is known as a heat sink
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单选题Which of the following modes of heat transfer does NOT require any physical contact between a warmer and a cooler substance?（）A
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单选题Which of the statements listed concerning heat transfer is correct?（）A
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单选题Which of the following statements is correct concerning heat transfer?（）A
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Heat transfer rate is affected most by the size of the heat sink involvedC
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单选题Which of the listed statements is correct concerning the starting of centrifugal pumps?（）A
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考题
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考题
单选题Which of the following statements is correct concerning the “flash point ” of a liquid?（）A
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考题
单选题Which of the lists forms of heat transfer, if any, is illustrated by the flow of combustion gases through a boiler?（）A
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Forced convection onlyC
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None
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CO2B
Methyl chlorideC
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考题
单选题Which of the listed statements is correct concerning refrigeration systems?（）A
Dehydrators must be used continuously in a refrigeration systemB
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Viscosity will decrease as temperature decreasesD
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Thermal expansion valve frozen openB
Suction gas heat exchanger bypassedC
Condenser clogged or fouledD
High pressure cutout switch inoperative
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