单项选择题
A.free B.fastened C.broken D.stuck
Before pumping up the crankcase oil,（） should be worked...
单项选择题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
Before being used the fuel service tank should be drain...
单项选择题Before being used the fuel service tank should be drained of （）.
A.soda solution B.mechanical impurities C.ballast D.water and residuals
Before a marine diesel engine is started the cylinders ...
单项选择题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
