제가 관계대명사 what과 that의 구별을선행사 + that + 불완전구조선행사x + what + 불완전구조이렇게 배웠거든요??

1. this is the only hint ______ i can give you.i can give you s v o 맞는데 that/what들어갈수있는건가요?2. this is the most exciting place ______ i have ever visited.i have ever visited가 완전인지 불완전인지 모르겠어요.3. he is the person who gives me ______ i want.me가 선행사인가요??

이거 세개를 모르겠어요 ㅠㅠ