The correct answer is the evolution of multicellular life. The evolution of multicellular was the most important event happened during the creation of the ozone layer. All of type of the organisms had evolved over time.
Astrocytes, <span>Star-shaped cells that anchor small blood vessels to neurons.</span>
Distance divided by time is <u>speed</u><u>.</u>
Explanation:
The distance you travel in a certain amount of time would be your speed.