Passage: World War I began as a clash of 20th-century technology and 19th-century tactics, with the inevitably large ensuing casualties. By the end of 1917, however, the major armies, now numbering millions of men, had modernised and were making use of telephone, wireless communication, armoured cars, tanks, and aircraft. Infantry formations were reorganised, so that 100-man companies were no longer the main unit of manoeuvre; instead, squads of 10 or so men, under the command of a junior NCO, were favoured. Artillery also underwent a revolution. In 1914, cannons were positioned in the front line and fired directly at their targets. By 1917, indirect fire with guns  was commonplace, using new techniques for spotting and ranging, notably aircraft and the often overlooked field telephone. Counter-battery missions became commonplace, also, and sound detection was used to locate enemy batteries.
How did sound help them? How many communication devices/tactics were modernized by the army? How many different things were major armies now using? How many fewer men made up the squads than had made up the companies? How many men smaller were the new squads compared to old infantry formations? How many people were in a squad? How many people were in command of an individual squad? How many things did the army modernize? How many types of vehicles were modernized by the army? How many years passed from the revolution in 1914 to when indirect fire with guns became commonplace? In which century did armies use telephones and wireless communication? What centuries clashed and during WWI? What weapon was now on the front line? Which tactic was used earlier, cannon fire or indirect fire with guns? Which things from these centuries clashed? Which was larger, the old infantry formations or the new squads commanded by a junior NCO? what were cannons made to fire at?