http://en.wikipedia.org/wiki/Trench_warfare#World_War_I:_tre...
As were the concepts of Schwerpunkt and penetration. These are clearly described in, e.g., Rommel's book about his WW1 infantry operations (http://en.wikipedia.org/wiki/Infantry_Attacks).
"Never in the field of human conflict was so much owed by so many to so few."
http://en.wikipedia.org/wiki/Never_was_so_much_owed_by_so_ma...
http://en.wikipedia.org/wiki/Trench_warfare#World_War_I:_tre...
As were the concepts of Schwerpunkt and penetration. These are clearly described in, e.g., Rommel's book about his WW1 infantry operations (http://en.wikipedia.org/wiki/Infantry_Attacks).