4. Today's Maths homework is much **more difficult** than yesterday's. 5. Emma is the **cleverest** person in our class. 6. Luigi's restaurant has **the best** pizza in town. 7. Monaco is one of **the smallest** countries in Europe. 8. The **longest** bridge in the world is in China - it's over 164 km long! 9. New York City is one of **the largest** cities in the world. 10. Take a bus - it's **cheaper than** a taxi. C. Dear [Friend's Name], I hope this letter finds you well. I wanted to let you know about an exciting science competition that our school is holding. The competition will test our knowledge and skills in various scientific fields, and I think it would be a great opportunity for us to showcase our talents. To participate, all you need to do is register with the science department by [deadline date]. Make sure to study hard and prepare well for the competition as there will be tough challenges ahead. I believe that we both have what it takes to excel in this competition, so let's give it our best shot and make our school proud! Looking forward to competing alongside you, [Your Name]