Combine each pair of sentences using a relative pronoun or relative adverb

Ex7. Combine each pair of sentences using a relative pronoun or relative adverb
1. That car belongs to Dr. Clark. Its engine is very good.
=> __
2. You sent me a present. Thank you very much for it.
=> __
3. This is Mrs. Jones. Her son won the championship last year.
=> __
4. Rod Lee has won an Oscar. I know his sister.
=> __
5. Do you know the music? It is being played on the radio.
=> __