In the second part, the circulatory system delivers the oxygen to body cells and picks up carbon dioxide from the cells in return.
(the circulatory system; delivers; the oxygen; to body cells; L:In the second part) (the circulatory system; picks up; carbon dioxide; from the cells; in return; L:In the second part)
the circulatory system the circulatory system
delivers picks up
the oxygen to body cells L:In the second part
carbon dioxide from the cells in return L:In the second part