English: Who was Frederick IV, Duke of Schleswig-Holstein-Gottorp?
translation: 石勒蘇益格-荷爾斯泰因-戈托普公爵腓特烈四世是誰？
translation: [石勒蘇益格-荷爾斯泰因-戈托普公爵腓特烈四世]是誰？
translation: 誰是腓特烈四世？
translation: 腓特烈四世是誰？