The answer should be reptiles!
The characteristics of reptiles are:
1. They are four-legged
2. They have an outer covering of scales
3. They breathe with the aid of lungs
4. Although most reptiles lay eggs, some also give birth to live young (fertilise internally)!
I hope this helps! :)
Answer: Organs are grouped into organ systems, in which they work together to carry out a particular function for the organism. For example, the heart and the blood vessels make up the cardiovascular system.
Ostrich is the biggest of all birds
