6. The United States is a highly developed nation with the highest GDP in the world, one of the highest per capita incomes in the world, and a high standard of living. Write a short essay that describes the following: a. Three factors that led to U. S. economic expansion and growth during the 20th century

b. Some of the challenges the United States still faces with its standard of living, despite its new global standing
Then, write an analysis paragraph in which you identify which of these challenges facing the U. S. standard of living, in your opinion, most needs to be addressed, and why. (20 points)