Here are the completed sentences:

1. Kings and Queens lived in **castles** in the past.
2. I think the **biggest** airport in London is Heathrow. There are hundreds of flights.
3. I always visit the British **museum** when I go to London. There are a lot of interesting things to see there and it’s a beautiful building.
4. I think the highest **mountain** in the world is Everest.
5. My dad loves the **pubs** in England. He likes the traditional drinks.
6. I never go on the **roller coaster** when we go to a theme park. I’m so scared.
7. We visited the **university** in Oxford where many famous people studied.
8. London is on the **river** Thames. You can take a boat trip on it.