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單項(xiàng)選擇題

Domestic water pump is started automatically by （） which operates as the water level falls to a predetermined level.

A.a level controller
B.a temperature switch
C.a pressure switch
D.a floating ball

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單項(xiàng)選擇題

In cargo crane, （） for lifting the load.

A.a hoisting motor
B.a luffing motor
C.a mooring motor
D.a slewing motor

單項(xiàng)選擇題

Manually operated band brakes may be fitted and （） will have a brake arranged to fail-safe.

A.the drive pump
B.the drive motor
C.the warp end
D.the purchase

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