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單項(xiàng)選擇題

The steam boiler is part of a closed loop steam, whereby, after the energy of the steam is used up and it becomes water again, （） is collected and returned back to the boiler for heating up again to steam.

A.the former
B.the first
C.the latter
D.the last

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單項(xiàng)選擇題

Care must be taken to condition the （）in the boiler to prevent scaling, and corrosion, which can weaken the pressure vessel.

A.water
B.fuel
C.steam
D.air

單項(xiàng)選擇題

The power and torque capability of the steering system must be such that the rudder can be swung from （）one side to（）the other side with the ship at maximum speed.

A.35°；35°
B.35°；30°
C.15°；15°
D.28°；60°

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