Russian soldiers write home while serving on the Eastern Front during World War I, circa 1915. (Photo by Hulton Archive/Getty Images)

A woman covers her face as a fire burns in the middle of town during an anti-G20 protest on July 7, 2017 in Hamburg, Germany. Authorities are braced for large-scale and disruptive protests as Leaders of the G20 group of nations arrive in Hamburg for the July 7-8 G20 summit. (Photo by Leon Neal/Getty Images)

Gengis “Lil Ceng” Ademoski (L) and Khaled “KC” Chaabi (R) of the four time world champion Berlin dance troupe “Flying Steps” strike a freeze on a piano played by muscian Jia Lim (C) of Singapore at the 17th century waterfront area of Nyhavn in build up to the Red Bull Flying Bach European Tour, a show that features the cultural clash of break dancing with the classical music of Johann Sebastian Bach, on August 30, 2011 in Copenhagen, Denmark. (Photo by Dean Treml/Red Bull via Getty Images)

A model wears a creation for Stephane Rolland's Spring-Summer 2016 Haute Couture fashion collection presented in Paris, Tuesday, January 26, 2016. (Photo by Francois Mori/AP Photo)

Children play on top of an old plane's fuselage at a dump site in Paranaque city, Metro Manila, Philippines January 21, 2017. (Photo by Ezra Acayan/Reuters)

A participant poses with his laptop during the 33rd Chaos Communication Congress on its opening day on December 27, 2016 in Hamburg, Germany. The annual event is bringing together 12,000 computer hackers and activists who will meet over the next four days to share expertise and discuss topics related to the society and the digital world. (Photo by Morris MacMatzen/Getty Images)

Baloo (R), a North American Black Bear, rubs snouts with his companion Shere Hkhan, a Bengal tiger, inside their shared enclosure at Noah's Ark animal sanctuary in Locust Grove, Georgia, USA, 28 August 2014. According to the facility, the pair and a lion named Leo, were confiscated at a young age from a drug dealer's basement in Atlanta, Georgia. Noah's Ark cares for about 100 different species of animals on a 250 acre farm since 1990. (Photo by Erik S. Lesser/EPA)

A woman takes a selfie in front of a Lunar New Year display featuring sheep at a shopping mall in Hong Kong, February 13, 2015. (Photo by Bobby Yip/Reuters)