Ƙirƙirar wani nau'i mai mahimmanci na wannan jumla Duke Island wani tsibirin ne a cikin tsibirin Gravina na Alexander Archipelago a kudu maso gabashin jihar Alaska na Amurka.
Tabbas, wani nau'i mai rikitarwa na jumla shine "Tsibirin Duke wani tsibiri ne a cikin Tsibirin Gravina na Alexander Archipelago a kudu maso gabashin Alaska, a, arewacin iyakar Kanada. "