<span>three most severe downturns in the United States economy since the 1920s were:
- The depression of 1921, happened because we receive a blowback for all the money we spent on world war I
- The Great Depression of 1929-1933 , happened because our investment to expand our business to all over the world
- The Great Recession of 2007, happen because of the mortgage crisis, causing Global financial crisis</span>
Answer:
Global population (more info below)
Explanation:
Global population increased due to increased sanitation, medicines, and food production. Hope I helped!
