Ans.
The cardiovascular system is made up of circulatory system (blood and blood vessels) and heart, through which blood circulates through out the body along with other substances.
The cardiovascular system carries oxygen, as oxygenated blood to the different body organs and collects carbon dioxide as deoxygenated blood and other waste products from various organs. Nutrients are also transported by the blood to different body cells of the body.
Thus, the three things the cardiovascular system transports is 'oxygen, nutrients, and carbon dioxide.'