单项选择题
Why is a warning sign displayed at the gangway or access point of a barge during cargo transfer（）.
A.To keep visitors away from the barge B.To prohibit smoking C.To prohibit open lights D.All of the above
单项选择题 Which would influence a magnetic compass（）.
单项选择题 Which is the correct procedure for anchoring a small to medium size vessel in deep water （）.
单项选择题 Which is a weekly publication advising mariners of important matters affecting navigational safety（）.
