A.low-velocity fog onlyB.a solid stream onlyC.a solid s……

单项选择题A CO2 portable extinguisher is annually 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

单项选择题A CO2 extinguisher on a ship which has lost 10% of its charge must be（）.

A.used at the earliest opportunity
B.hydrotested
C.recharged
D.weighed again in one month

单项选择题A branch line valve of a fire extinguishing system on a ship must be marked with the（）.

A.maximum pressure allowed at that branch
B.name of the space or spaces which it serves
C.date of the last maintenance inspection
D.pressure needed to maintain an effective stream at that point

单项选择题（），as the chemical extinguisher agent，should be used for an electric fire.

A.dry chemical or foam
B.foam or soda acid
C.carbon dioxide or foam
D.carbon dioxide or dry chemical

单项选择题The danger of a charged hose left unattended on deck with the nozzle open is（）.

A.the hose could burst
B.the nozzle end will whip about causing damage or injury
C.water damage to vessel's cargo or structure
D.personnel might trip over the hose