Which statement best describes air pressure at high altitudes? (Points : 3)
Air pressure decreases as altitude increases.
Air pressure increases as altitude increases.
Air pressure does not change as altitude increases.
It is impossible to accurately measure air pressure at high altitudes.

air pressure decreases as altitude increases. this is because air pressure is caused by the gravity of earth, the gravity pulls on the air, compacting it and making a pressure.But as we go higher, gravity decreases, causing less pull on the air resulting in less air pressure.

In general, air pressure decreases as elevation increases because there is less atmosphere pushing down on the object. So "Air pressure decreases as altitude increases."