Answer:
The circulatory system
Explanation:
The circulatory system works together to provide your brain with a supply of oxygen.
The circulatory system provides your brain with a constant supply of oxygen-rich blood while your brain regulates your heart rate and blood pressure. Even seemingly unrelated body systems are connected
They convert glucose into usable energy.
They are made with Sexual reproduction
where's the answer choices?
the answer is 1,2,3,5