We need to translate the English news title into natural Korean. The title: "How 'secret' underground energy could heat every home in Cardiff". We need to produce Korean translation. Let's think: "How 'secret' underground energy could heat every home in Cardiff". In Korean, maybe: "카디프의 모든 가정을 데울 수 있는 '비밀' 지하 에너지의 비밀" but we need to keep the nuance. "How 'secret' underground energy could heat every home in Cardiff" could be translated as: "카디프의 모든 가정을 데울 수 있는 '비밀' 지하 에너지의 비밀". But we might wa...