Fill in the blanks with 'this', 'that', 'these', or 'those'.

1. This is Paul's robot. 2. These are Tina's dolls. 3. Those are Bill's cars. 4. This is Gina's tea set. 5. This is Alice's ball. 6. Those are Tom's pencils. 7. This is Julia's bike. 8. That is Martin's radio.