单项选择题
A.Repeat the message using any other channel on which you might attract attention
B.Key the microphone several times before transmitting again
C.Turn up the volume on the receiver before transmitting again
D.Report the problem to the head electrician
单项选择题 What is one of the FIRST actions you should take after abandoning and clearing away from a vessel?（）
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?（）
单项选择题 The survival craft is manufactured with fire retardant（）.