单项选择题
Which bearing will carry the load on two small points diametrically opposite to each other?（）
A.Needle B.Tapered roller C.Roller D.Ball
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（）.
单项选择题 A refrigeration system compressor crankcase is sweating or unusually coldThis is an indication of（）.
