World War II was a conflict between 1939 and 1945 that involved all the world's major countries. It was the most destructive war in history and millions of people were killed. It was fought between the Axis (Germany, Japan, and Italy) and the Allies (Britain, the US, and the Soviet Union among others).
They were too large and expensive - typically a computer would fill a room and would have to have its own power supply.
All are true because Russia needs Crimea and Africa is so messed up because of the boundaries and opium war forced China into accepting European trade terms
