单项选择题
What is NOT a distress signal?（）
A.Red flares or red rockets B.Continuous sounding of fog signaling apparatus C.International Code Flags "November" and "Charlie" D.Basket hanging in the rigging
单项选择题 What is meant by the term “radio silence”?（）
单项选择题 Wat is NOT required in the radiotelephone log?（）
单项选择题 Upon receipt of a distress message，a merchant vessel is bound to proceed to the scene of the distress. Under which of the following cases would this NOT be true?（）
