97免费在线观看视频,亚洲综合自拍网,黄色毛片免费观看,热久久综合网,免费看日产一区二区三区狠狠操av,久久久涩涩涩,在线精品免费视频,人人插天天干,久久91精品国产91久久

單項選擇題

Before pumping up the crankcase oil,（） should be worked by hand to minimize corrosive action on the liners.

A.the indicators
B.the starting valves
C.the cylinder lubricators
D.the turning gear

你可能感興趣的試題

單項選擇題

Before being used the fuel service tank should be drained of （）.

A.soda solution
B.mechanical impurities
C.ballast
D.water and residuals

單項選擇題

Before a marine diesel engine is started the cylinders and pistons must be （）.

A.cooled to appropriate temperature
B.warmed up gradually to appropriate temperature
C.opened up and renewed
D.ground and polished

<nobr id="npe9h"></nobr>

<strong id="npe9h"></strong>