单项选择题
A（）is the intersection of the surface of a sphere and a plane passing through the center of the sphere.
A.great circle B.small circle C.large circle D.general circle
单项选择题 A “Mediterranean moor” should be used when（）.
单项选择题 （）is not a step for anchoring preparation.
单项选择题 When anchoring，good practice requires 5 to 7 fathoms of chain for each fathom of depth. In deep water you should use（）.
