单项选择题
A.trick-wheel B.follow-up control C.six-way valve D.Rapson slide
The internal force of a material, which tends to resist...
单项选择题The internal force of a material, which tends to resist deformation when subjected to external forces, is known as （）.
A.stress B.strain C.shear strength D.ultimate tensile strength
An increase in rotor clearances in a rotary pump will （...
单项选择题An increase in rotor clearances in a rotary pump will （）.
A.increase discharge pressure B.decrease pump capacity C.decrease pump cavitation D.decrease reaction ring clearance
Sweating of the refrigeration system compressor crankca...
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
