单项选择题
A.forming temporary eyes in lines B.joining two lines of equal size C.keeping line from unlaying or fraying D.joining two lines of different size
The size of wire rope is determined by the（）.A.number o...
单项选择题The size of wire rope is determined by the（）.
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
