Qí / gé / fēi / fáng / xiàn / shì / Dé / guó / zài / dì / yī / cì / shì / jiè / dà / zhàn / qī / jiān / xiū / jiàn / de / zhòng / yào / fáng / yù / gōng / shì齐格菲防线是德国在第一次世界大战期间修建的重要防御工事。The Siegfried Line was an important defensive fortification built by Germany during World War I.