无码高清视频|成人自拍视频|欧美成人午夜无码A片秀色直播|草美女视频网站|美女被操网站在线观看

單項(xiàng)選擇題

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

微信掃碼免費(fèi)搜題