单项选择题 LOW ABOUT 300 MILES SOUTHWEST OF LISBON 1004 MOVING SLWLY SOUTHEAST COMMA FILLING 1006 BY MIDNIGHT.This phrase is likely to be under the heading of（）.

单项选择题 Information for updating nautical charts is primarily found in the（）.

单项选择题 In revised editions of Admiralty charts the（）are corrected first．