单项选择题
One disadvantage of using regular dry chemical (sodium bicarbonate) in firefighting is that（）.
A.it can break down under high heat and emit noxious fumes
B.it will decompose under prolonged storage and lose its effectiveness
C.fire has been known to flash back over the surface of an oil fire
D.it is ineffective in fighting fires in high-voltage electrical equipment
相关考题
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单项选择题
One advantage of the all-purpose nozzle is that it（）.
A.can fit any size hose
B.converts a stream of water into a fog
C.increases the amount of water reaching the fire
D.can spray two streams of water at the same time -
单项选择题
Once a vessel has loaded packaged hazardous cargo，the cargo spaces shall be inspected. The spaces shall also be inspected at least once in every 24 hours. The only exception to daily inspection is when（）.
A.a vessel is equipped with an automatic smoke or fire detecting system
B.the cargo hatches are of steel construction
C.the cargo is of a nonflammable type
D.there is sufficient fire protection located on the main deck adjacent to the cargo hatch -
单项选择题
On a ship，when may a work vest be substituted for a required life preserver?（）
A.To replace a damaged life preserver
B.For use during fire drills
C.For use during boat drills
D.At no time
