单项选择题
吊杆停用时,稳索必须要收起来。()
A. When the derrick is stopped, the guy must be stowed. B. When the derrick is stopped, the guy must be topped. C. When the derrick is stopped, the guy must be lowered. D. When the guy is stopped, the derrick must be stowed.
单项选择题 作为一名值班水手,你必须懂得如何调整吊杆。()
单项选择题 很多船上在每个舱口处都有两个吊杆及两台起货机。()
单项选择题 重吊杆用于吊大的重件。()