单项选择题
During a training exercise a submarine indicating that a torpedo has been fired will send up smoke from a float. The smoke’s color will be（）.
A.black B.red C.orange D.yellow
单项选择题 During a fire drill on a ship，what action is required?（）
单项选择题 Due to the hazards involved with Halon extinguishers on a ship，the size II extinguisher may only be used（）.
单项选择题 Dry chemical fire extinguishers are effective on which type(s) of fire?（）
