单项选择题
An aneroid barometer is an instrument（）.
A.used to measure the speed of wind B.in which the pressure of air is measured C.that tells which dirction a storm is coming from D.used to measure the height of waves
单项选择题 An emergence sea anchor may be constructed by type of extinguisher?（）.
单项选择题 An engine compartment gasoline fire requires which type of extinguisher?（）.
单项选择题 An example of a messenger is a（）.
