单项选择题
A. heavy cargo derrick B. heavy deck C. jumbo boom D. heavy block
The（）(千斤索) is a wire used to take the weight off.A. lig...
单项选择题The（）(千斤索) is a wire used to take the weight off.
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
