Explain why a nerve impulse need both an electrical impulse and a chemical impulse? Please answer in detail

What are the three major branches of natural science? • earth and space science, life science, physical science •earth and space science, physical science, chemistry •physical science, life science, chemistry •life science, chemistry, physics

How does the atmosphere to make earth livable? check all that apply. causes the seasons contains oxygen provides warmth creates important nutrients blocks harmful energy from the sun plz like !

4. glenn andrews recently bought a motorcycle for $3,950. if he had to pay 6% sales tax on the bike, what was the total cost of the motorcycle?