The heart, blood and blood vessels work together to service the cells of the body. Using the network of arteries, veins and capillaries, blood carries carbon dioxide to the lungs and picks up oxygen. From the small intestine, the blood gathers food nutrients and delivers them to every cell.
The gradual movement of the continents across the Earth’s surface throughout geological time.
between 5.6 and 13 cm long
I believe the lowest orange square would
