单项选择题 On which vessels are the officers and deck crew allowed to operate under a two-watch system on voyages of less than 600 miles? （）

单项选择题 Maritime Administration personnel may be allowed in the pilothouse upon the responsibility of the（）.

单项选择题 In writing up the logbook at the end of your watch，you make an error in writing an entry. What is the proper way of correcting this error? （）