单项选择题 opes or wires attached to derricks to prevent them from swinging during cargo handling operations are（）.

单项选择题 On your vessel，a wire rope for the cargo gear shows signs of excessive wear and must be replaced. In ordering a new wire for this 10-ton boom，what safety factor should you use?（）

单项选择题 On an anchor windlass，the wheel over which the anchor chain passes is called a（）.