单选题Noise in a refrigeration compressor can be caused by （）.Aworn bearings and piston pinsBslugging due to flooding backCtoo much oil in circulationDAll of the above
单选题
Noise in a refrigeration compressor can be caused by （）.
A
worn bearings and piston pins
B
slugging due to flooding back
C
too much oil in circulation
D
All of the above
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