单项选择题 （）are increasingly used as main engine on merchant vessels, because they have a high Hp/Weight ratio.

单项选择题 During check on top clearance in main bearings, turn the crankthrow for the relevant cylinder unit to （） and stop the lube oil circulating pump.

单项选择题 Just after stopping the engine while the oil is still circulating.Check that uniform oil jets appear from all the oil outlet grooves in the crosshead bearing lower shell and the guide shoes.The oil flow from （） must be compared from unit; there should be a similarity in the flow patterns.