The Cỉculatory system is an organ system that permits blood to everywhere in the body and transport nutrients, oxygen, carbon dioxide, ...to help fighting diseases ,.... The main parts of the Circulatory system are heart , lungs , veins , vessels, arteries,...
I think its C. The long neck of a giraffe
no because Separation of oxygenated and deoxygenated blood in the heart of three types of animals. The three-chambered frog heart mixes oxygenated and deoxygenated blood in the ventricle. Therefore, the body never receives fully oxygen-rich blood.
