单项选择题
A.always be wide open when the compressor restarts
B.continue to operate as if the system were in operation
C.remain open until evaporator pressure equalizes, then close until the compressor restarts
D.always be completely closed until the compressor restarts
单项选择题 To add refrigerant to the high side of an air conditioning system, you should introduce the refrigerant through the （）.
单项选择题 When adding oil to a refrigeration system, precautions must be taken to ensure that （）.
单项选择题 In a refrigeration system, if the cooling water to the condenser fails, the（）.