- 問題詳情:Dolphinsliveinadarkunderwaterworld.It’softenimpossibletoseeeachotheroranythingelsearoundthem,sosoundplaysanimportantroleintheirsurvival.Tocommunicatewitheachother,dolphinsproduceallkindsofsounds.Onlyotherdolphinsunderstandwhatthesoundsmean.S...
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