单项选择题
A fifteen-pound CO2 extinguisher（）.
A.contains 15 pounds of CO2 B.weighs 15 pounds when full of CO2 C.has 15 pounds of pressure at the nozzle D.weighs 15 pounds when empty
单项选择题 Records of tests and inspections of a cargo vessel’s fire extinguishing systems shall be（）on board until the vessel’s Certificate of Inspection expires.
单项选择题 Accumulations of oily rags should be（）.
