Human loyal friend - dog

The dog was domesticated by the early humans from the gray wolf. The domestication time was from 40,000 years ago to 15,000 years ago, it was the earliest domesticated animal. According to statistics, there are more than 1,400 species of dogs in the world, of which more than 500 are classified. There are more than 240 kinds of world famous dogs. A large number of studies from recent genetic studies have shown that there are about 450 existing dogs.

The dog's facial features are human-like and the limbs are more healthy. They walked up and swayed, and they were so happy. Under normal circumstances, the dog is about eight decimeters in length and its weight will not exceed 35 kg...

The dog is flexible and is a favorite animal. Almost no dog in the world is demented, and no dog is not loved or loved. Not only that, the dog's reaction is also very agile. When you see the presence of mice and worms, the dog shows its own ability to quickly capture the "prey" that is tight; in the dog's line of sight, almost no "prey" can get rid of its "palm" heart".

The dog's food intake is small, but it is very picky. The daily food intake of a dog is about one-third of the human food. It only eats fish, meat or other bones. Most vegetables and fruits do not like to eat...

The dog's intelligence is also unusual in the lower animal kingdom, and is one-fourth of the higher animal--"human" intelligence. Dogs that are trained manually can do many difficult moves: catching tiny items falling from the air in extremely low altitudes; holding one's hand on the human hand, like a human being... ...

Xiaoxian Middle School, the first day: Xie Wei