单项选择题
Vessels carrying（）must not willfully wash decks or holds.
A.general cargo B.steel products C.harmful cargo D.machinery
单项选择题 The transportation of dangerous cargo in packages is governed by（）.
单项选择题 The telegram AFTER UNLOADING PROCEED MANILA IN BALLAST indicates that the ship will proceed to Manila（）.
单项选择题 The sign used to caution persons approaching the gangway of a tank barge during cargo transfer reads（）.
