单项选择题
The tackle that raises and lowers the boom is（）.
A.the cargo fall B.The cargo hoisting wire rope C.the topping lift D.the cargo whip
单项选择题 The strongest of the natural fiber ropes is（）.
单项选择题 The square knot is used for（）.
单项选择题 The rope which is rove from the truck to be used with a bos’n chair is called a（）.
