单项选择题
A six-strand composite rope made up of alternate fiber and wire strands around a fiber core is called（）.
A.Spring lay B.Lang lay C.Cable lay D.Alternate lay
单项选择题 A rope made of a combination of wire and fiber is known as（）.
单项选择题 A permanent chain chasing system is used to（）.
单项选择题 A pelican hook（）.
