单项选择题 Instead of whipping an end of a line，a temporary means of preventing the line from unraveling is to tie a（）.

单项选择题 In the manufacture of wire rope，if the wires are shaped to conform to the curvature of the finished rope before they are laid up，the rope is called（）.

单项选择题 In order to retrieve an inflatable life raft and place it on deck，you should heave on the（）.