单项选择题
The only cylindrical chart projection widely used for navigation is the（）.
A.Lambert conformal B.Mercator C.aximuthal D.gnomonic
单项选择题 The notice which is based on original information is indicatedby（）nexttothenotice number.
单项选择题 What areessentialto ensure the effective implementationoftheship securityplan?（）
单项选择题 Which factor has the greatest effect on the amount of gain required to obtain a fathometer reading?（）
