单项选择题 Low compression of diesel engine may result from （）

单项选择题 Leaky exhaust valve will result in which of the following?（） (1) high exhaust temperature; (2) low compression pressure; (3) low firing pressure.

单项选择题 Large marine diesel engines of crosshead construction generally have two systems of lubrication: a total loss system feeding the （） and a recirculation system lubricating the running gear and cooling the piston.