Answer:
Phobos
Phobos is nearing Mars at a rate of six feet (1.8 meters) every hundred years; at that rate, it will either crash into Mars in 50 million years or break up into a ring.
Explanation:
Permitting the exchange of nutrients and gases between the blood and tissue cells is the primary function of capillaries. Capillaries are the smallest blood vessels , they are only one cell thick, and they act as sites of the transfer of oxygen and other nutrients from the bloodstream to the body tissues. Additionally, they also collect carbon dioxide, waste materials and fluids for return to the veins.