单选题If a refrigeration compressor is running continuously without lowering the temperature in the refrigerated space, the trouble may be （）.Aa shortage of compressor oilBwarm food in the refrigeratorCexcessive condenser cooling waterDa shortage of refrigerant
单选题
If a refrigeration compressor is running continuously without lowering the temperature in the refrigerated space, the trouble may be （）.
A
a shortage of compressor oil
B
warm food in the refrigerator
C
excessive condenser cooling water
D
a shortage of refrigerant
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