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

<strong id="lo8wm"><th id="lo8wm"></th></strong>

單項選擇題

（）can be used to prevent hydraulic system overloaded or keep the pressure of oil outlet from pump constant.

A.Overflow valve
B.Reducing valve
C.Balancing valve
D.Reducing valve or balancing valve

你可能感興趣的試題

單項選擇題

The symbol (GB786√1-93) at right side represents （）

A.overflow valve
B.reducing valve
C.relief valve
D.sequence valve

單項選擇題

The symbol (GB786√1-93) at right side represents （）

A.overflow valve
B.reducing valve
C.relief valve
D.sequence valve