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

Heat damage to fuel injection nozzles on small high-speed diesel engines, can be prevented by()

A.employing fuel oil as a cooling medium
B.preventing hard carbon deposit on nozzle tips
C.avoiding fuel oil temperature exceeding builder’s specification
D.ensuring good metallic contact between nozzles and cylinder heads

微信掃碼免費(fèi)搜題