单项选择题
It is very important for every sailor （）the characteristics of the ropes so that they can be for right jobs.
A.knowing B.know C.to know D.knew
单项选择题 This windlass （）now.
单项选择题 The blocks and gooseneck of the jumbo need （）.
单项选择题 One （）of the pilot ladder has been damaged. Please repair it at once.
