Light bulbs were the power source used in factories during the industrialization
I think there could be many answers. For example Horn of Africa, by sea, or just by trade routes
The answer is Galileo, however, a scientist much earlier then Galaleo, named Anaxagoras also discover this. However, I believe credit is given to Galileo.
After the war ended, the global economy began to decline. In the United States, 1918–1919 saw a modest economic retreat, but the second part of 1919 saw a mild recovery. A more severe recession hit the United States in 1920 and 1921, when the global economy fell very sharply.
