麻烦各位朋友帮我解答下这句英语我现在学习新概念英语第四册30课遇见几句难点句子麻烦各位朋友帮我解答下!(1)and th

麻烦各位朋友帮我解答下这句英语
我现在学习新概念英语第四册30课遇见几句难点句子麻烦各位朋友帮我解答下!(1)and the hazards of navigation presented by the irregularities in depth of the shallow water close to the land这就话书上翻译为,以及靠近陆地潜水区的深浅不一定能给船带来危险,这里的the hazards of navigation presented by the irregularities 该怎么理解这句话呢?