A Thorneycroft motor van as used during World War I. (Photo by Topical Press Agency/Getty Images). August 1914

Marc Berthod of Switzerland during the Audi FIS Alpine Ski World Cup Men's Super Combined on February 12, 2012 in Sochi, Russia. (Photo by Vianney Thibaut/Agence Zoom/Getty Images)

A security personnel plays with a girl in the compound of a health and rest centre which serves as a temporary accommodation for refugees from eastern regions of the country in the town of Korostyshiv, Zhytomyr region, Ukraine, July 30, 2015. More than 400 people who left eastern Ukraine due to a military conflict have arrived at the sanatorium in Korostyshiv since the summer of 2014, according to representatives. (Photo by Valentyn Ogirenko/Reuters)

Merit: A Night at Deadvlei. The night before returning to Windhoek, we spent several hours at Deadveli. The moon was bright enough to illuminate the sand dunes in the distance, but the skies were still dark enough to clearly see the milky way and magellanic clouds. Deadveli means “dead marsh. The camelthorn trees are believed to be about 900 years old, but have not decomposed because the environment is so dry. (Photo and caption by Beth McCarley/National Geographic Traveler Photo Contest)

Migrants rush as they try to get on a train heading to the border with Serbia at the train station of Gevgelija, on the Macedonian-Greek border, on August 9, 2015. Non-EU Serbia's frontier with Hungary, which is in the bloc's passport-free Schengen zone, has become a major crossing point for the huge numbers of migrants entering the EU. (Photo by Dimitar Dilkoff/AFP Photo)

A Hindu devotee displays his inked hand after taking part in the religious festival of Holi in Vrindavan, in the northern state of Uttar Pradesh, India, March 8, 2017. (Photo by Cathal McNaughton/Reuters)

Tourists take a panoramic view of Kuala Lumpur from a skybox during a media preview at Kuala Lumpur Tower in Kuala Lumpur, Malaysia, 05 May 2016. Skybox, 421 metres above ground level will be the latest tourists attraction at Kuala Lumpur Tower, the 7th tallest freestanding tower in the world. (Photo by Ahmad Yusni/EPA)

Students at the Cuba's National Ballet School (ENB) watch a class from outside the classroom in Havana, Cuba, October 12, 2016. Catherine Conley, the first American full-time student at Cuba's prestigious National Ballet School, hopes to gain an edge back home by learning the powerful Cuban style with its dazzling turns and jumps. (Photo by Alexandre Meneghini/Reuters)