单项选择题
What information will a distress alert contain?（）
A.nature of distress B.type of assistance required C.course and speed and time at which the information was recorded D.A, B, C are all right
单项选择题 The ARQ mode should be applied（）.
单项选择题 It is required that ships proceeding at sea should keep continuous watch on（）.
单项选择题 General radio communications in the global system are those between（）concerning the management and operation of the ships and may have impact on their safety.
