10 most difficult World War I riddles

The Borchardt C-93 semi-automatic pistol was designed by Hugo Borchardt in 1893 based upon the Maxim toggle-bolt design.. With about 1,100 manufactured by Loewe and nearly 2,000 more produced by Deutsche Waffen und Munitionsfabriken, the Borchardt C-93 was the first mass-produced semi-automatic pistol.

The battle incorporated many of the newer tactics of 1918, in particular tanks. The attack was an overwhelming success with light casualties in an extremely short amount of time.

The Paris Gun was a German long-range siege gun used to bombard Paris during World War I. The gun was capable of firing a 94 kilogram (210 lb) shell to a maximum altitude of 40 kilometers (25 miles, 131,000 ft). It was the first time for human-made object to reach stratosphere.

The A7V was a tank introduced by Germany in 1918, during World War I. They were used in action from March to October 1918, and were the only tanks produced by Germany in World War I to be used in combat.

Manfred Albrecht Freiherr von Richthofen, also known as the "Red Baron", was a German fighter pilot during World War I. He is considered the ace-of-aces of the war, being officially credited with 80 air combat victories. The Fokker Dr I it became famous as the aircraft in which Manfred von Richthofen gained his last 19 victories, and in which he was killed on 21 April 1918.

Since 1914, the Allied naval blockade of Germany throttled maritime commerce with Germany, forcing Germany to develop substitutes for products (Ersatz) such as tea composed of ground raspberry leaves or catnip, and coffee substitute using roasted acorns. This process was not limited to food, numerous chemical substitutes such as synthetic rubber were also developed at the time.

The Paris Gun was the name given to a type of German long-range siege gun, several of which were used to bombard Paris during World War I. They were in service from March to August 1918. When the guns were first employed, Parisians believed they had been bombed by a high-altitude Zeppelin, as the sound of neither an aeroplane nor a gun could be heard.

The Battle of the Somme was fought by the armies of the British and French empires against the German Empire. More than three million men fought in this battle and one million men were wounded or killed, making it one of the bloodiest battles in human history.

The Imperial German Embassy in U.S. decided to warn passengers not to sail aboard Lusitania. It placed a warning, advertisement in 50 American newspapers, just next to an advertisement for the Lusitania's return voyage.

Although the term human torpedo is usually associated with Japan during the WW II, it was actually developed much earlier. On 1 November 1918, an Italian manned torpedo nicknamed Mignatta sank the Austrian battleship Viribus Unitis and the freighter Wien using limpet mines. It was the first successful attack of its kind.