问题：
[单选题]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 minute
参考答案：
B
相关内容
- ● One of the ignal，other than a ditre ignal，that can be ued by a veel to attract attention i a(n)（）.
- ● Which ignal i recognized a a ditre ignal?（）.
- ● A veel hall lacken her peed，top，or revere her engine，if neceary，to（）.
- ● When a veel ee the other ahead or nearly ahead，by night he could ee the mathead light of the other in a line or nearly in a line or both ide light，（）hall be deemed to exit.
- ● （）cargo mean to check all cargo loaded into or dicharged from a veel.
- ● After a veel tranmit the original ditre meage，what ignal hould be ent to allow hip to take RDF bearing?（）
- ● A veel not under command ound the ame fog ignal a a veel（）.
- ● Acknowledgement by you of receipt of a ditre meage from a veel which，beyond any poible doubt，i not in your vicinity and i a long ditance away mut be made when（）.
- ● You can indicate that your veel i in ditre by（）.
- ● When a veel ignal her ditre by mean of a gun or other exploive ignal，the firing hould be at interval of approximately（）.
- ● Continuou ounding of a fog whitle by a veel i a ignal（）.
- ● Berthing mean bringing a veel to her berth until（）.
