There was a time when a C meant average. The average GPA at four-year colleges and universities has risen from 2.52 in the 1950s to 3.11 in 2006. And according to Stuart Rojstaczer, a former Duke University professor and founder of GradeInflation.com, GPAs only keep rising. At some colleges, Rojstaczer says, over 50% of the grades given are A's.
Trench warfare was caused by an advance in defensive weaponry. The machine gun was too heavy to be used as a mobile weapon, and therefore was placed into a fixed position. Barbed and concertina wire was also heavily used.
Four underlying causes of war. The assassination of Archduke Franz Ferdinand signalled the rapid slide into world war, but this wasn't the only cause. There were underlying causes in the run-up to the First World War. In the 1930s, historians argued that there were four underlying long-term causes of the First World War: 1  Nationalism-the belief that your country is better than others. 2  This made nations assertive and aggressive.