单项选择题
Which of the following components provides a direct source of seawater for the fire main system?（）
A.Rose box B.Sea chest or spool piece C.Sluice valve D.Fire pump stuffing box
单项选择题 Fires involving combustible metals are classified as （）.
单项选择题 Which of the following gases represents the greatest threat to personnel safety in an engine room where the exhaust is leaking from a diesel engine?（）
单项选择题 Seawater may be used for drinking water （）.
