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

Which of the listed cylinder liner surface conditions indicates proper lubrication?()

A.Dull black appearance
B.Bright appearance
C.Thin layer of lacquer
D.Thick oily film

微信掃碼免費(fèi)搜題