单项选择题
The safe working load of each derrick is five （）.
A.tones B.tonnages C.tons D.dunnage
单项选择题 All the （）in hold No.3 should be bagged.
单项选择题 I was told not to use （）in handling bagged cargoes.
单项选择题 Before opening the hatch covers, all cleats are to be （）.
