The three functions of the circulatory system among the statements provided are:
- transports nutrients
- bringing oxygen to cells
- removing wastes from the body
The other options, such as "breaking down nutrients," "helping to fight off diseases and infections," and "removing water and carbon dioxide," are not primary functions of the circulatory system itself. While the circulatory system can aid in immune response and removal of gases, the core functions focus on transporting nutrients, oxygen, and waste products.