Помогите,пожалуйста

Choose the correct answer:

1. Tom's car is as big as /the biggest his friend's.

2. Who is shorter than /the shortest person in your family?

3. Who is more independent than / the most independent person you know?

4. These sofas are more comfortable than / the most comfortable ours.

5. My brother is taller than /the tallest in the class.

6. Is Jason's dog older than /the oldest yours?

7. Who is the best /better than singer in the world?