Complete the sentences with who, which, or where.

1. A builder is someone **who** builds houses. 2. A cooker is a machine **which** cooks food. 3. An airport is a place **where** people catch planes. 4. A pilot is someone **who** flies planes. 5. A pencil is something **which** you use for writing. 6. An author is someone **who** writes books. 7. A cinema is a place **where** you go to watch movies.