单项选择题
Fire extinguishers of sizes III，IV，and V are designated as（）.
A.portable B.semi-portable C.fixed D.disposable
单项选择题 Fire and abandon ship stations and duties may be found on the（）.
单项选择题 Fire alarm system thermostats are actuated by（）.
单项选择题 Except in rare cases，it is impossible to extinguish a shipboard fire by（）.
