更多"In slow speed two-stroke engines,（）"的相关试题:
[单项选择]The fresh air coming in through the inner air ports, is compressed by（） to a higher pressure.
A. the cylinder head
B. the cross-head
C. the moving piston
D. the stationary piston
[单项选择]I am a fresh air fiend.（）
A. 我是邪神，喜欢新鲜空气。
B. 我酷爱室外的活动。
C. 我这人特喜欢新鲜空气。
D. 我是个喜爱户外运动的人。
[单项选择]A charge of fresh air is drawn into the engine cylinder and then （） by the moving piston（） very high pressure.
A. pressed；to
B. pressurized；with
C. pushed；in
D. compressed；to
[单项选择]The fresh air intake of the inert gas system（）.
A. prevents the flue gas from falling below 3% content of oxygen
B. allows the inert gas piping to be used for gas freeing the tanks
C. opens when there is excessive vacuum on the deck water seal
D. enables outside air to mix with and cool hot flue gasses
[单项选择]The crankshafts of medium speed engines are almost invariably solid （） from a single piece of steel.
A. forged
B. cast
C. made
D. shrunk
[单项选择]Pistons of marine medium speed diesel engines may be made of （） in order to keep the weight down for balancing purpose at high speed.
A. lead
B. forged steel
C. alloy steel
D. aluminum alloy
[单项选择]Critical speed in diesel engines occurs when engine torque pulsations become （）
A. opposed to the crankshaft rocking couple
B. resonant with the crankshaft natural frequency
C. critical fore and aft crankshaft vibrations
D. horizontal whipping motions of the crankshaft
[单项选择]Some medium and high-speed diesel engines require reduction gear units to provide a useful propeller speedIn most reduction gears, the bull gear（）
A. must churn the oil in the sump
B. is connected to the propeller shaft
C. is driven at the highest RPM
D. compensates for alignment variations between the engine and pinion gear
[单项选择]Crankshafts of medium speed engines are （） from a single piece of steel.
A. unusually solid welded
B. never be solid forged
C. almost invariably solid forged
D. almost invariably be welded
[单项选择]Medium speed engines have a （） power to weight ratio than the slow speed two strokes, but due to the higher speeds tend to have （） maintenance intervals.
A. higher；reduced
B. higher；increased
C. lower；reduced
D. lower；increased
[单项选择]The fresh water generator produces fresh water （）.
A. by cooling sea water
B. by heating sea water
C. by evaporation of sea water
D. by purifying sea water
[单项选择]When the density of water is 1000,i.e.in fresh water and in summer zone a ship may load to the upper edge of the line marked（）.
A. S
B. T
C. W
D. F
[单项选择]Air receivers installed in starting air systems are to be （）.
A. cylindrical in shape with service connections located at the top and bottom
B. opened and made available for inspection during biannual inspections provided
C. with automatic drain traps for the removal of moisture
D. so installed as to make the drain connections effective under extreme conditions of trim
[单项选择]Air entering an air-cooled refrigeration system is indicated by （）.
A. frosting of the liquid line
B. higher than normal head pressure
C. a clear sight glass
D. abnormally cold reefer boxes
[单项选择]Compressed air is supplied by air compression to （）.
A. the air receivers
B. the starting valves
C. the cylinder covers
D. the distributors
[单项选择]Air line lubricators are used in compressed air systems to lubricate （）.
A. the suction and discharge valves
B. tools and equipment served by compressed air
C. air line reducing valves
D. all of the above
[单项选择]Air conditioning is the process of treating air to control （） its temperature, humidity, cleanliness and distribution to meet the comfort requirements of the occupants of the conditioned space.
A. instantaneous
B. instantaneously
C. simultaneous
D. simultaneously
[单项选择]In reference to air conditioning, when air attains the maximum amount of moisture it can hold at a specific temperature, it is said to be （）.
A. superheated
B. saturated
C. condensed
D. convected
[单项选择]The quantity of cooled air delivered by an air conditioning unit should （） the sum of the quantity of air re-circulated to the unit and the quantity mechanically exhausted.
A. balance
B. not balance
C. be more than
D. be less than
