单项选择题
Who can contact the Designed Person?（）
A.the designated person B.the captain C.all senior officer D.all officers and crew
单项选择题 When shall the stand-on vessel change course and speed?（）
单项选择题 Carbon dioxide flooding system is used for extinguishing fires because it reduces the concentration of oxygen in the air to（）.
单项选择题 Where shall the key to C02 room be kept?（）
