Reducing free surfaces has the effect of lowering the（）.

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? （）

A.Towing vessels
B.Offshore supply vessels
C.Barges，when manned
D.All of the above

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

A.Chief Officer
B.Navigator
C.most senior person present from the Maritime Administration
D.officer in charge of the watch

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? （）

A.Carefully and neatly erase the entry and rewrite it correctly
B.Cross out the error with a single line，write the correct entry，and initial it
C.Blot out the error completely and rewrite the entry correctly
D.Remove this page of the log book and rewrite all entries on a clean page

单项选择题If your passenger vessel is fitted with a loudspeaker system，it must be tested at least once （）.

A.every week
B.a day
C.every trip
D.a watch or once a trip，whichever is shorter

单项选择题Functions aboard a tanker or tank barge such as connecting，disconnecting，and topping off must be supervised by（）.

A.any certificated tankerman
B.the Master of the vessel
C.the officer of the watch
D.the person designated as "person in charge"