单项选择题
What is the most important source of information to be used in correcting charts and keeping them up to date（）.
A.Fleet Guides B.Notice to Mariners C.Sailing Directions D.Pilot Charts
单项选择题 Weekly Notices are dated for the（）appropriate to the week they are issued on the UKHO website.
单项选择题 Weekly NMs are available without subscription from appointed（）.
单项选择题 Vessels should not anchor or trawl in the vicinity of pipelines and are（）in the pipeline area shown on the chart.
