单项选择题
A.dredging ( of anchor )
B.dragging ( of anchor )
C.weighing anchor
D.walking out anchor
单项选择题 Pan-Pan is to be used to announce（）.
单项选择题 Pan-Pan repeated three times over the radiotelephone indicates which type of message will follow?（）
单项选择题 Place on deck, in mess rooms,etc.,assigned to crew and passengers, where they have to meet according to the muster list when the corresponding alarm is released or announcement made means（）.