介绍长江下游航道标志被碰的情况，通过对被碰标志的原因分析，提出减少标志被打的措施。
The situations of bumping to marks in the Yangtze River downstream waterway are introduced, through analysis to the causes of which, measures for reducing bumping to marks are presented.
灯塔是进入海港航道的标志。
灯塔是进入海港航道的标志。
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