你可能感興趣的試題

Before doing any work on a hydraulic system equipped with accumulators, you should（）

A.drain the accumulators and purge with oxygen
B.bleed off all stored energy from the accumulators completely
C.charge the accumulators to prevent system energy loss
D.pump the hydraulic fluid into the accumulators to prevent fluid loss

單項(xiàng)選擇題

The ability of lubricating oils to resist viscosity changes during temperature changes is indicated by the（）

A.American Petroleum
B.Institute number viscosity index number
C.Seconds Saybolt Furol number
D.Seconds Saybolt Universal number