The main sign by which birds can be recognized among vertebrates.

The most important feature in them is that the bodies of birds are covered with feathers, while other vertebrates do not have such feathers on their bodies.

One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.