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.
Trench warfare. Trench warfare, warfare in which opposing armed forces attack, counterattack, and defend from relatively permanent systems of trenches dug into the ground. The opposing systems of trenches are usually close to one another. Trench warfare is resorted to when the superior firepower of the defense compels the opposing forces to âdig inâ so extensively as to sacrifice their mobility in order to gain protection. 1  A trench system may begin simply as a collection of foxholes hastily dug by troops using their entrenching tools.