관계부사 문제 빈칸과 이유 알려주세요

각 문장의 빈칸에 들어갈 말을 알려주시고, 답인 이유도 설명 부탁드려요.
빈칸에 들어갈 말이 다른 하나를 찾는 문제예요.
1. I know the place ______ she got up this morning.
2. This is the park ______ I first met Lucy.
3. The hotel ______ we stayed was very small.
4. Mr. Smith lives in the house ______ is made of wood.
5. I will build beautiful houses ______ children will sing and play.