When the ship is going to enter into the harbor, ____.
A. change from heavy fuel oil to diesel oil for main engine
B. pumping out bilge water
C. change sea chest from high level one to lower level one
D. test emergency generator
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In reducing engine speed to an efficient propeller speed by the use of reduction gears, _______.
A. speed and torque are both reduced
B. speed is reduced and torque remains unchanged
C. speed is reduced and torque is increased
D. speed is sometimes unchanged while torque is increased
Which of the listed devices may be used as a digital device？
A. variable resistor
B. diode
C. strain gauge
D. thermistor
Because the circulating water is in a closed loop,_______is installed to cater for expansion and contraction of the water at different conditions of operation.
A. an expansion joint
B. a drain tank
C. a head tank
D. a contraction tank
航空运输是指航空承运人按照()要求，将旅客或货物由一地运抵另一地的过程。
A. 运输合同
B. 客票
C. 货单
D. 机票
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