A soldier poses with a Hythe Mk III Gun Camera during training activities at Ellington Field, Houston, Texas in April of 1918. The Mk III, built to match the size, handling, and weight of a Lewis Gun, was used to train aerial gunners, recording a photograph when the trigger was pulled, for later review, when an instructor could coach trainees on better aiming strategies. (Photo by Harry Kidd/WWI Army Signal Corps Photograph Collection via The Atlantic)

A flight deck crew prepares to launch a F18 Super Hornet from the deck of the USS Eisenhower off the coast of Virginia, December 10, 2015 in the Atlantic Ocean. US Defense Secretary Ash Carter visited the carrier with India's Minister of Defense Manohar Parrikar to demonstrate US Navy aircraft carrier flight operations. (Photo by Mark Wilson/Getty Images)

A child looks at window cleaners work while dressed in sheep (C) and monkey costumes, denoting animal signs of the Chinese zodiac calendar, during an event marking the upcoming end of the year at a hotel in Tokyo, Japan, December 21, 2015. According to the zodiac calendar, 2015 is the year of the sheep and 2016 is the year of the monkey. (Photo by Thomas Peter/Reuters)

Saint Nicholas poses with students during a traditional parade in central Brussels, Belgium December 3, 2016. (Photo by Yves Herman/Reuters)

President Barack Obama with does the tango with a dancer during the State Dinner at the Centro Cultural Kirchner, Wednesday, March 23, 2016, in Buenos Aires, Argentina. (Photo by Pablo Martinez Monsivais/AP Photo)

Rahma, 19 (L), pictured with her 10-year old brother Fahad on June 21, 2016 in Kano, Nigeria. A teenage girl born without limbs lives her life in a plastic bowl. Rahma Haruna is a bright, happy girl, despite suffering from a mystery condition that stopped her arms and legs developing properly – leaving her practically limbless and in constant pain. The 19-year- old, from Kano, Nigeria, was born a healthy baby but when she turned six months old her growth came to a sudden halt and she stopped hitting key development milestones. Rahma’s family do their best to provide her with a fulfilling life and transport her around the village in a plastic bowl. Rahma said: “They help me a lot. How do they? They give me anything I need”. Rahma died on 25 December 2016. (Photo by Sani Maikatanga/Barcroft Images)

Photographers take photographs of the Large Air Tanker (LAT) C-130 Hercules, also known as “Thor”, as it drops a load of around 15,000 litres during a display by the Rural Fire Service ahead of the bushfire season at RAAF Base Richmond Sydney, Australia, September 1, 2017. (Photo by David Gray/Reuters)

Animal rights activists, including musician Kris Reichert, center, hold up signs with writing in Italian reading; “Leather: a lethal look” and “I wouldn't wear animal skin even if I were dead” as they stage a demonstration in front of Milan's Duomo gothic cathedral, Italy, Wednesday, September 20, 2017. Milan Fashion Week previews kick off Wednesday with Gucci, leading up to the awards on Sunday night. (Photo by Luca Bruno/AP Photo)