According to one hypothesis, life on earth emerged from (bluegreen algae/ amino acids/ molten metals/ crustal rocks) in the presence of large amounts of gasses seeping from deep ocean vents. ANother process called primordial soup suggests that the formation of life was due to the effects of (lightning/sunlight/gravity/meteorites) in earths atmosphere.
Hey there!
Airplanes must be pressurized when flying at high altitudes so that the oxygen levels stay normal for us to breathe. The higher you go up, the thinner the air gets, which causes breathing problems for us humans.
Thank you!