单项选择题
A.overspeed trip
B.audible/visual alarm
C.the ships/boats general alarm
D.reserve oil storage tank
单项选择题 A viscous damper, as used on a marine diesel, is a sealed precision built device which dampens the torsional vibrations in the （）.
单项选择题 A diesel engine is operating at 1800 RPM and driving a propeller at 600 RPMWhat is the speed reduction ratio?（）
单项选择题 High diesel engine cooling water temperatures can be caused by （）.