Passengers wait for a train to depart from the Hankou Railway Station in Wuhan, central China's Hubei province, Friday January 13, 2017. Officials expect that Chinese travelers will make almost 3 billion trips during the holiday travel rush that starts runs through Feb. 21. These trips include intercity flights, trains and local bus rides to villages for China's 1.4 billion people. (Photo by Chinatopix via AP Photo)

Steam emerges from a cooling tower of the nuclear power plant Leibstadt near Leibstadt, Switzerland, November 18, 2014. (Photo by Arnd Wiegmann/Reuters)

Cheerleaders let their hair fly as they perform prior to a German first division Bundesliga soccer match between 1. FC Cologne and Bayern Munich in Cologne, Germany, March 4, 2017. (Photo by Michael Probst/AP Photo)

The unromantic gypsies. Children boxing in a gypsy camp in Kent, England on July 1, 1951. Like all boys these gypsy lads like to try their hand at boxing. Encouraged by their friends they fight it out on Corke's Meadow. Few Romanies now live a life of wandering romance. Most are like the three hundred squatters of Corke's Meadow, Kent, which is part of a “gypsy problem” that involves about 100,000 today. Of those about 25,000 can be rightly called gypsies, the rest are Mumpers and Posh-rats and Hobos. Corke's Meadow has both kinds. “Picture Post” cameraman Bert Hardy photographs the Corke's Meadow gypsies in their encampment. (Photo by Hulton-Deutsch Collection/Corbis via Getty Images)

A Femen activist is led away by French police in Henin-beaumont, northern France, Sunday, May 7, 2017. Voters across France are choosing a new president in an unusually tense and important election that could decide Europe's future, making a stark choice between pro-business progressive candidate Emmanuel Macron and far-right populist Marine Le Pen. (Photo by Francois Mori/AP Photo)

The Pink Floyd inflatable pig floats next to Broadcasting House to promote their new exhibition at the V&A museum, in London, Britain May 10, 2017. (Photo by Neil Hall/Reuters)

A man pours water on his camel on a hot summer day in Ahmedabad, India, May 18, 2017. (Photo by Amit Dave/Reuters)