A.先關(guān)出油閥再開(kāi)回油閥 B.先開(kāi)回油閥再關(guān)出油閥 C.兩閥都打開(kāi)
A.主缸高于輪缸 B.主缸與輪缸相等 C.輪缸高于主缸
A.出油閥和回油閥均開(kāi)啟 B.出油閥關(guān)閉而回油閥開(kāi)啟 C.雙閥均關(guān)