单项选择题
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（）.
单项选择题 On a ship，when may a work vest be substituted for a required life preserver?（）
单项选择题 On a ship，watertight doors should be operated（）.