单项选择题
The receiver used in a refrigeration system（）
A.stores liquid refrigerant B.collects non-condensable gases C.allows refrigerant sub-cooling D.prevents compressor surging
单项选择题 The purpose of the refrigeration system low pressure cutout switch is to （）
单项选择题 A pressure drop in the liquid line of a refrigeration system may cause（）
单项选择题 In a direct expansion type multi-box refrigeration system, the compressor is set up to cycle on and off by the（）
