单项选择题
A.number of strands B.number of wires in each strand C.circumference D.diameter
The signal man assisting a crane operator has his arm e...
单项选择题The signal man assisting a crane operator has his arm extended with his fingers closed and thumb pointing upward. This is the signal to（）.
A.raise the boom B.raise the hook C.raise the boom and hook D.check the boom stop
The rope which is the lightest is（）.A.manilaB.nylonC.po...
单项选择题The rope which is the lightest is（）.
A.manila B.nylon C.polypropylene D.dacron
The rope which is rove from the truck to be used with a...
单项选择题The rope which is rove from the truck to be used with a bos’n chair is called a（）.
A.gantline B.life line C.strop D.whip
