问题
单项选择题
When a vessel signals her distress by means of a gun or other explosive signal,the firing should be at intervals of approximately().
A.10 minutes
B.1 minute
C.1 hour
D.3 minutes
答案
参考答案:B
When a vessel signals her distress by means of a gun or other explosive signal,the firing should be at intervals of approximately().
A.10 minutes
B.1 minute
C.1 hour
D.3 minutes
参考答案:B