The blood vessel which carries oxygenated blood from the lungs to the heart is : (a) main artery (b) pulmonary artery (c) main vein (d) pulmonary vein
All veins carrying deoxygenated blood combine into a single vein called_____.
Veins and arteries carry blood. Which of these carry blood : (a) away from the heart ? (b) back to the heart ?