In the past, whales had legs. From whales no longer having legs, its technically a mutation. With this, it means they can no longer go onto land, so they learned to adapt to the water.
Answer:
the central nervous system and the peripheral nervous system
Explanation:
The nervous system has two main parts:
The central nervous system is made up of the brain and spinal cord.
The peripheral nervous system is made up of nerves that branch off from the spinal cord and extend to all parts of the body.
The answer is D.
With mechanical advantage, less work is put in for a better result.
It can apply force in a shorter distance, but increase distance itself.
