GROUNDWATER is the largest source of freshwater on earth.
<span>Carbon dioxide, a waste product of
metabolism, travels from the blood to the alveoli, where it can be
exhaled. Between the alveoli is a thin layer of cells called the
interstitium, which contains blood vessels and cells that help support
the alveoli.</span>
Sensors and computer-vision algorithms work together to ensure a driverless car complies with traffic laws and minimizes the chance of collisions. Meanwhile, GIS navigation guides the vehicle along the best route to its destination.
A) 5 percent of Antarctica is ice free
