Relative dating best helps determine fossil age. It's where layers of sedimentary rock and fossils pile up on top of each other; the oldest fossils being in the bottom layer and the youngest in the top.
The planetary body that Spirit was designed to explore the wide ranges of soil and rocks for clues of the water activity on Mars. Spirit specifically landed at the Gusev Crater which was before, a possible lake in a giant crater.
ALVEOLI are the very small air sacs where the exchange of oxygen and carbon dioxide takes place. CAPILLARIES are blood vessels in the walls of the alveoli. Blood passes through the capillaries, entering through your PULMONARY ARTERY and leaving via your PULMONARY VEIN.
