Compare continents and countries in terms of population, density and migration

Africa and North America: Africa has a higher population density, more North America, and more migrations in North America.
China and Brazil: The number and density in China are greater; migration is the strongest in Brazil.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.