问题：
[单选] With VIT unit the timing of fuel injection of an engine can be regulated automatically according to the （）.
ship draft。pitch。engine load。oil viscosity。
问题：
[单选] Worn out ring grooves should be （） to standard dimension after being welded.
machined。bored。honed。drilled。
问题：
[单选] You increased the （） to 150 tons that’s why the fuel oil （）.
pumped speed；came out。pumping rate；overflowed。flowing rate；leaked out。flowed speed；spilled out。
问题：
[单选] You must take good care of the drainage cock of the air control systemBecause （） leads scale formed which might malfunction the pilot control valve and other instruments.
the temperature。the rust。the pressure。the humidity。
问题：
[单选] With （）, the corrosion problems are much reduced in a central cooling system.
no equipment in contact with sea water。less equipment in contact with fresh water。more equipment in contact with sea water。less equipment in contact with sea water。
问题：
[单选] General, the best way for replacement of lamp is （）.
after the point is reached at which the failures begin to increase rapidly。before the point is reached at which the failures begin to increase rapidly。before the point is reached at which the failures begin to increase slowly。after the point is reached at which the failures begin to increase slowly。
问题：
[单选] The trouble-free life of an engine indicates （）.
the period of time during which no trouble occurs to the engine。no trouble will occur to the engine all its life。trouble may occur freely to the engine。no matter what you do to the engine, no trouble will occur during this period。
问题：
[单选] When we say that two objects have relative motion, we mean （）.
the distance between them remains the same。the distance between them is changing。the position between them is not changing。their positions to the earth remain the same。
问题：
[单选] Among the main propulsion units on board the ship with the same capacity, the lightest one is（）.
steam engine。steam turbine。gas turbine。diesel engine。
问题：
[单选] The essential part of the diesel engine, whose function is to convert the heat energy into the mechanical power, is the （）.
crankshaft。piston。connecting rod。bearing。
