While steaming slowly in the harbor，no ship is （） to exceed the speed limited．

单项选择题The height of eye correction is smaller than geometrical dip because of （）.

A. the angle between the horizontal and the line of sight to the visible horizon
B. index error
C. parallax
D. terrestrial refraction

单项选择题（）amplify charted detail and contain information needed for safe navigation.

A.Admiralty Sailing Directions
B.Admiralty List of Lights
C.Admiralty List of Signals
D.Admiralty Notices to Mariners

单项选择题Admiralty Sailing Directions are Kept up to date by （）.

A.corrections
B.publications
C.supplements
D.alterations

单项选择题Every new supplement to the Sailing Directions （） the previous one．

A.enforces
B.cancels
C.corrects
D.replenishes

单项选择题In Admiralty Sailing Directions，STRIPES is the word used to indicate （）marking.

A.horizontal
B.vertical
C.diagonal
D.vertical or diagonal