1. United States: The United States is the largest economy in the world and one of the most powerful military forces in the world. The United States is one of the most developed industrialized countries in the world with a vast territory and rich resources.

2. China: China is the most populous country and the second largest economy in the world. China has a long history and culture and is one of the oldest civilizations in the world.

3. Brazil: Brazil is the largest country in South America and one of the countries with the largest land area in the world. Brazil is rich in natural resources and diverse in culture, and is one of the most important economies in South America.

4. Canada: Canada is one of the countries with the largest forest coverage in the world, with a vast territory and rich resources. Canada is one of the most developed countries in the world, with highly perfect social welfare and high-quality education system.

5. Russia: Russia is the largest country in the world, rich in resources and vast in territory. Russia is an important industrial country with strong military strength and strategic position.

These countries play an important role in global politics, economy and culture, and have a far-reaching impact on world development and progress.