单项选择题
A. light derrick B. union purchase C. topping lift D. heavy derrick
The （）(双杆联吊) is that two booms are used with a single h...
单项选择题The （）(双杆联吊) is that two booms are used with a single hook.
A. derrick B. union purchase C. topping lift block D. crane
The （）(包装货) is loaded and unloaded by cargo sling.A. ba...
单项选择题The （）(包装货) is loaded and unloaded by cargo sling.
A. bagged cargo B. packed cargo C. cased cargo D. deck cargo
The（）(折叠式舱盖) can fold slowly.A. rolling type hatch cove...
单项选择题The（）(折叠式舱盖) can fold slowly.
A. rolling type hatch cover B. side-rolling hatch cover C. folding type hatch cover D. automatic hatch cover
