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單項選擇題

The（） only allows for adjustment of temperature in each room by the occupant manually controlling the air volume admitted.

A.central air condition system
B.high velocity system
C.low velocity system
D.single duct system

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單項選擇題

The volute of centrifugal pump also acts as a diffuser converting （）into pressure head.

A.mechanical energy
B.heat energy
C.potential energy
D.kinetic head

單項選擇題

A centrifugal impeller consists of a number of vanes curving （） from the direction of rotation.

A.backwards
B.forwards
C.upward
D.downwards

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