It was World War 2 because during that war, they made powerful bombs, and items that need special technology. When the war ended, we needed more powerful war items, so to help us make them, we invented the computer to use it as a blue print when making the weapons, mechanical items, such as robot arms, to place details into certain area's.
Hope this helps. :)
<span>b. Glaciers pushed them out of their homeland.</span>