單項(xiàng)選擇題The rate of heat transfer in a water-tube auxiliary boiler can be increased by （）.

A.operating the boiler at less than normal water level
B.installing fins on the firesides of water-tubes
C.increasing the amount of excess air to the burners
D.treating the boiler water with chemical oxygen scavengers


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1.單項(xiàng)選擇題The term “proper metering”, as applied to a diesel fuel injection system, can be best defined as （）.

A.delivering the same quantity of fuel to each cylinder for each power stroke according to engine load
B.maintaining the metering adjustment for a reasonable period under all load conditions
C.timing fuel injection to obtain maximum power and good fuel economy
D.distributing the fuel to all parts of the combustion chamber for proper combustion

2.單項(xiàng)選擇題Connecting rods in a diesel engine are used to connect the （）.

A.engine to the bed
B.rocker arm to the camshaft
C.crankshaft to the gear train
D.piston to the crankshaft

3.單項(xiàng)選擇題Fuel oil transfer systems used onboard diesel propelled vessels are required to have （）.

A.two fuel oil transfer pumps provided where one is to be independent of the main engine
B.two fuel oil transfer pumps, with a combined capacity exceeding the maximum consumption of the main engine
C.engine driven transfer pumps and only used in constant speed applications
D.the capacity of the engine driven pump exceed the consumption rate of the engine to which it is attached

4.單項(xiàng)選擇題In a diesel engine lube oil system, which of the following parts should be lubricated first?（）

A.Camshaft beatings
B.Main bearings
C.Piston crowns
D.Cylinder walls

5.單項(xiàng)選擇題Before starting a diesel engine that has an engine driven lube oil pump, the engineer should （）.

A.open the bypass line
B.cut in the lube oil cooler
C.pressurize the lube oil system
D.top off the expansion tank