Question

the circulatory system is... our heart, blood vessels, and blood. our heart, lungs, brain, and kidneys. our blood vessels, blood, and kidneys. our heart, lungs, and blood vessels.

Explanation:

The circulatory system consists of the heart which pumps blood, blood vessels that carry blood, and blood itself which transports substances like oxygen and nutrients. Lungs, brain and kidneys are not part of the circulatory - system's basic components.

Answer:

our heart, blood vessels, and blood.