单项选择题
For which of the listed classes of fire combinations would carbon dioxide be most suitable as the extinguishing agent （）.
A.Class "A" and class "B" B.Class "B" and class "C" C.Class "A" and class " C" D.Class "C", class "D", and class "E"
单项选择题 Most lifeboats are equipped with （）.
单项选择题 While reading the station bill, you find "three (3) short blasts on the whistle and three (3) short tings on the general alarm bells," this signal is for （）.
单项选择题 Hydrocarbon vapors are usually detected by the use of the （）.
