人类到底有多少星座呢英文

The question of how many human beings are in the world is a complex one, and it's not something that can be answered with a simple number. However, we can discuss some of the ways in which humans are classified and how this classification relates to our understanding of the universe.

One way to classify humans is by their physical characteristics. There are over 7 billion people on Earth, but only about 20% of them are considered \