1. The Iguazu Falls are the most impressive (impressive) waterfalls in the world.
2. The Atacama Desert is the driest place on Earth. (dry)
3. The River Nile is the longest Earth. (long) river on
4. The Amazon Rainforest is the biggest (big) rainforest in the world.
5. Vatican City is the smallest country in the world. (small)
6. Bondi Beach is the most popular (popular) beach in Sydney