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單項選擇題

0il fires are best extinguish by（）.

A.cutting off supply of oxygen
B.removing the fuel
C.cooling below the ignition temperature
D.spraying with water

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單項選擇題

0n a crane ,the boom indicator tells the operator what angle the boom angle is compared to the（）.

A.vertical position
B.horizontal position
C.boom stop angle
D.minimum radius angle

單項選擇題

0n a vessel ,a C0₂ extinguisher is checked by（）.

A.reading the gage pressure
B.weighing the extinguisher
C.discharging a small amount of CO₂
D.seeing if the seal has been broken

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