Answer:b) The air at high altitudes are less dense, so its harder to breathe.
Explanation:
AS altitude increases, the air pressure drops. This reduces the amount of gas molecules in the air so the air becomes less dense compared to air closer to sea level.
Nests, small organisms such as lizards, snakes, small birds, rock formations, skeletons of small animals.
Vascular tissue composed of xylem<span> (red) and </span>phloem<span> tissue (green, between the</span>xylem<span> and </span>cortex<span>) surrounds the pith. Collenchyma cells are elongated cells with unevenly-thickened walls . They provide structural support, mainly to the stem and leaves.</span>
