单项选择题
Cargo that is suitable for carriage on Ro-Ro vessels includes（）.
A.trailers B.rolling vehicles C.containers D.All of the above
单项选择题 Cargo securing for Ro-Ro is based on the concept of（）.
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?（）.
