A dirty diesel engine oil filter element can best be detected by （）.

单项选择题In an auxiliary boiler steam and water system, the highest pressure will be in the （）.

A.steam stop valve
B.dry pipe
C.feedwater system
D.generating tubes

单项选择题If the jacket water temperature of an operating diesel engine suddenly rises above normal, the cause can be attributed to （）.

A.an overfilled expansion tank
B.excess chromate treatment of the jacket water
C.a clogged raw water sea suction
D.cavitation erosion of the heat exchanger tubes

单项选择题The possibility of damage from operating a diesel engine at critical speeds is reduced by the use of（）.

A.an isochronous governor
B.elastic engine mounts
C.a vibration damper
D.a cast iron bed plate with good flexible qualities

单项选择题The air supplied to a diesel engine is compressed to （） (1) provide heat for the ignition of the fuel (2) decrease injection delay

A.(1) only is correct
B.(2) only is correct
C.both (1) and (2) are correct
D.neither (1) or (2) are correct

单项选择题In a normally operating diesel engine, the main cause of lubricating oil contamination in the crankcase is a result of the （）.

A.metal particles loosened by wear
B.air when no air cleaners are used
C.condensation of water vapors
D.breakdown of the lubricating oil by dilution