单项选择题
Before opening the hatch covers, all cleats are to be （）.
A. released B. secured C. taken away D. sent out
单项选择题 A （）is used for lifting long heavy cargo.
单项选择题 （）cargo is unloaded by huge grabs on cranes or by large grain elevators.
单项选择题 At the discharging port, tankers pump the oil ashore using （）.
