单项选择题
How long must the records of tests and inspections of fire fighting equipment on board a ship be retained on board?（）
A.6 months B.1 year C.3 years D.Until the next inspection for certification
单项选择题 Each crewmember has an assigned firefighting station. This assignment is shown on the（）.
单项选择题 An advantage of an ABC dry chemical over a carbon dioxide extinguisher is（）.
单项选择题 After using a Halon extinguisher，it should be（）.
