单项选择题
You will find information about the duration of slack water in the （）.
A.Tidal Current Tables B.Tide Tables C.American Practical Navigator D.Sailing Directions
单项选择题 （）amplify charted detail and contain information needed for safe navigation.
单项选择题 Admiralty Sailing Directions are Kept up to date by （）.
单项选择题 Every new supplement to the Sailing Directions （） the previous one．
