单项选择题
A cargo boom is a（）.
A.double sized mattress consists of more than 890 coils B.spar extending from a mast or a king post C.flap（Becker rudder）can be fitted to the rudder’s trailing edge D.bridle arrangement having a long beam of the length of the container
单项选择题 A 6x19 wire rope would be（）.
单项选择题 A 6x12，two-inch wire rope has（）.
单项选择题 A “sheepshank” is used to（）.
