单项选择题
Two mooring lines may be placed on the same bollard and either one cast off first if（）.
A.the eye of the second line is dipped B.the mooring lines are doubled C.the bollard has two horns D.one of the lines is a breast line
单项选择题 Tugs sometimes shackle a length of chain in the towline in order to（）.
单项选择题 Towlines should be inspected for chafing where the towline（）.
单项选择题 The strongest of the natural fibers is（）.
