单项选择题
A chart with a natural scale of 1:160，000 is classified as a（）.
A.sailing chart B.general chart C.coast chart D.harbor chart
单项选择题 A chart projection depicting the poles and a small area on either side of a connecting meridian，that is sometimes used for star charts，is the（）.
单项选择题 A chart position enclosed by a square is a(n)（）.
单项选择题 A change of a documented vessel’s name can only be made by the（）.
