What relative pronoun can be used to join the sentences: 'The movie is about a detective. Solving a mysterious case.'?

Which relative pronoun can be used to join the sentences: 'The house is beautiful. My grandparents live in it.'?

What relative pronoun can be used to join the sentences: 'This is the girl. Invited us to her birthday party.'?

Which relative pronoun can be used to join the sentences: 'That is the car. We bought it last week.'?

What relative pronoun can be used to join the sentences: 'She is the teacher. I admire her dedication.'?

Which relative pronoun can be used to join the sentences: 'The man is my uncle. Lives in New York.'?

What relative pronoun can be used to join the sentences: 'This is the park. We had a picnic there.'?

Which relative pronoun can be used to join the sentences: 'He is the student. Won the spelling bee.'?

What relative pronoun can be used to join the sentences: 'She is the girl. I met her at the party.'?

Which relative pronoun can be used to join the following sentences: 'This is the book. I borrowed it from the library.'?