单项选择题
The color of rockets，shells，or rocket parachute flares used to indicate that the vessel is in distress and requires immediate assistance is（）.
A.white B.green C.red D.yellow
单项选择题 On every vessel，distress signals must be stowed（）.
单项选择题 If you log a distress message，it must include the（）.
单项选择题 If you hear the firing of a gun at one minute intervals from another vessel，this indicates that（）.
