1. Fertilization is internal, you can breed without water.
2. Propagate with the help of yolk-rich eggs, covered with parchment coating (propagation on land).
3. Dry skin without glands prevents water loss.
4. The respiratory surface of the lungs increases, it allows to improve the supply of oxygen to the body.
5. An incomplete septum in the ventricle reduces blood mixing, and oxygen-rich blood enters the organs.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.