单选题When it is necessary to open a refrigeration system for repairs and the system will be open for more than a few minutes, the open ends of the system should be （）.AdehydratedBpurgedCpluggedDevacuated
单选题
When it is necessary to open a refrigeration system for repairs and the system will be open for more than a few minutes, the open ends of the system should be （）.
A
dehydrated
B
purged
C
plugged
D
evacuated
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