Particular care is needed when navigating in the vicinity of（）as very few of these features have been fully surveyed to modern standards to determine their correct position，full extent，or the least depth over them.

A.a small error in bearing or in laying it down on the chart has a greater effect in misplacing the position the longer the line to be drawn
B.all scales are kept updated for vital information by Notices to Mariners
C.the larger the scale of the chart，the greater the detail that can be shown on it
D.the mariner using the medium scale charts for passage along a coast need not transfer on to a large scale for short distances

A.1 minute of longitude
B.1 degree of longitude
C.1 minute of latitude
D.1 degree of latitude

A.the final judge of the reliance the mariner can place on the information given
B.its immediate importance cannot always be verified before promulgation
C.through imperfections in the survey on which it is based，or subsequent alterations to the topography or sea floor
D.deferring the promulgation of certain less important information