Bird

Author: Huaiyi
Publisher:
Publish Date: 1999-04-01
Features: Birds are vertebrates covered with feathers, and their body temperature is constant. The body temperature of most birds is higher than that of humans. All birds have two legs, and their mouths do not have teeth. The bird's beak has a special name called a "beak." All birds have a pair of wings. Most birds can fly, while a few cannot fly and can only walk. Many people believe that the ancestors of birds are dinosaurs that went extinct on Earth millions of years ago. Birds, like dinosaurs, hatch their young from eggs.