单项选择题
Short cycling of a refrigeration compressor refers to （）.
A.frequently grounding out B.frequently starting and stopping C.running too fast D.running too slow
单项选择题 When a flash-type evaporator is to be secured for an extended period of time, the entire unit should be drained, cleaned, and （）.
单项选择题 Condensate must be drained periodically from the air compressor receivers to prevent （）.
单项选择题 Overheating of a hydraulic system may be a result of （）.
