Answer:
The Great Oxidation Event (GOE), sometimes also called the Great Oxygenation Event, Oxygen Catastrophe, Oxygen Crisis, Oxygen Holocaust, or Oxygen Revolution, was a time period when the Earth's atmosphere and the shallow ocean experienced a rise in oxygen, approximately 2.4 billion years ago (2.4 Ga) to 2.1–2.0 Ga during the Paleoproterozoic era.
Explanation:
Please mark as brainliest please
The Sahara desert is important for a multiple of reasons. One is that although it is a desert, there are many fertile areas of land making it great for farming and supporting life. It also acts as a natural barrier in between north and south Africa, which was able to impact trade with the South, slowing down innovation on both sides.
B, provide systematic irrigation.
