单项选择题
Cargo securing for Ro-Ro is based on the concept of（）.
A.solid packing B.rapid loading and discharge C.vessel loaded full and down to her marks D.palletized cargo
单项选择题 Cargo booms must be weight tested to recertify the Safe Working Load (SWL) every（）.
单项选择题 By regulation，cargo tanks must be inert before and during what operation?（）.
单项选择题 By regulation，cargo tank atmosphere must be inert before and during which operation?（）
