1. her argument is______ makes me upset.2. this is an invention ______ is very useful.3. what i learned is _________ money is not all.4. it was your advice_________ gave me succcess.5. my belief is________ the present is the most precious.2번은 관계대명사 that이고 4번은 강조용법이고 3,5번은 접속사 보어의that인데 1번이 정확치가 않아요.1번은 관계대명사의 what 일까요? 일단, 답은 1번이라고 되어 있는데....... 자세한 설명좀 부탁드리겠습니다.