单项选择题
A.one turn of wire on the first stud from each side of the detachable link
B.two turns of wire on the second stud from each side of the detachable link
C.three turns of wire on the third stud from each side of the detachable link
D.four turns of wire on the fourth stud from each side of the detachable link
单项选择题 Forces within a drilling unit have caused a difference between the starboard and port drafts. This difference is（）.
单项选择题 For the purpose of training and drills，if reasonable and practicable，rescue boats on an OSV must be launched with their assigned crew（）.
单项选择题 For safety reasons，when assistance towing（）.