【高三英语一句语法填空,句子有点难分析InDauphinIsland,approximately90milestotheeastofthepoint19thehurricanemadelandfall(山崩),thesandthatcomprisedthebarrierisland20(transport)acrosstheislandintotheMississippi】

　　高三英语一句语法填空,句子有点难分析

　　InDauphinIsland,approximately90milestotheeastofthepoint19thehurricanemadelandfall(山崩),thesandthatcomprisedthebarrierisland20(transport)acrosstheislandintotheMississippiSound(海峡),21（push）theislandtowardsland.最好帮我解释为什么那样填,特别要告诉我哪个句子是并列句还是从句哦,