单项选择题
Sailors should know the （）(安全工作负荷量)of derricks.
A. safe working load B. safety work load C. safe work load D. safe working loading
单项选择题 Liquid bulk cargo is loaded and discharged by （）(泵).
单项选择题 （）(湿货)must be kept away from dry cargo.
单项选择题 This is （）(甲板货).
