单项选择题
Sweating of the refrigeration system compressor crankcase is caused by （）.
A.too much superheat B.insufficient superheat C.suction pressure too low D.excessive refrigerant returning to the compressor
单项选择题 Which bearing will carry the load on two small points diametrically opposite to each other?（）
单项选择题 Refrigeration system compressor crankcase sweating is an indication of （）.
单项选择题 Operating a rotary pump at speeds in excess of design requirements could cause（）.
