单项选择题
Red lights may appear on（）.
A.horizontally banded buoys B.vertically striped buoys C.yellow buoys D.spherical buoys
单项选择题 Preventer bars are fitted on lifeboat releasing hooks to prevent（）.
单项选择题 Please tell your tallymen to（）out the marks in the holds during discharging.
单项选择题 Please shift some light cargo to fill it（）.
