1. Which now-controversial military utility was first developed during the war?
The Hewitt-Sperry Automatic Aircraft was an unmanned aerial torpedo developed by the U.S. Navy. The device used gyroscopes and a barometer for control and direction but was ultimately too inaccurate to use in combat. (Photo: Naval History and Heritage Command)
2. Which item of clothing was popularized by World War I soldiers?
The trench coat replaced the heavy serge coats initially worn by British and French soldiers during the war. Both Burberry and Aquascutum claim to have invented it. (Photo: Bettmann/CORBIS)
ski mask (balaclava)
3. Germany tried a new concept called Sommerzeit — what is it?
daylight saving time
Germany and Austria-Hungary were the first to adopt the practice of shifting their clocks to conserve coal during the war. Other countries — including the U.S. and Great Britain — followed suit, but many reverted back to standard time after the war. It was implemented again during World War II. (Photo: Topical Press Agency/Getty Images)
summer vacation for children
4. Which French word came into standard English use during the war?
One of the earliest appearances of the word in English is 1916, referring to a need to be concealed from enemy view. (Photo: Keystone View Company/Hulton Archive/Getty Images)
5. Which item for women found its start on the battlefield?
Battlefield nurses re-purposed the cellulose bandages they were using on soldier’s wounds for menstrual pads because they were absorbent, clean and cheap. Kotex introduced a commercial version in the 1920s. (Photo: Hulton Archive/Getty Images)
6. Which advance in naval warfare was invented during World War I?
The HMS Furious was built as a battle cruiser and later converted into an aircraft carrier when the Royal Navy removed a turret and added a flight deck. Edwin Dunning became the first person to land an aircraft on a moving ship when he did so on the HMS Furious in 1917. (Photo: Hulton Archive/Getty Images)