Cheng Chen (R), a 27-year-old worker at a state-owned enterprise, poses for a photograph with his nephew who is wearing his home-made Iron Man armour, in Xuzhou, Jiangsu province April 13, 2015. It cost Cheng about 500 yuan ($81 USD) to make the armour, which weighs about 4 kilograms, with plastic boards and LED lights, local media reported. (Photo by Reuters/Stringer)

A pair of gloved hands are dwarfed by the furry paws of Boris the Polar Bear at the Point Defiance Zoo & Aquarium's animal health care hospital Saturday, February 23, 2013 in Tacoma, Washington. (Dean J. Koepfler/Tacoma News Tribune/MCT)

Participants wait backstage during the Miss Wheelchair India beauty pageant in Mumbai November 26, 2014. Seven women from across India participated in the country's second wheelchair beauty pageant, which aims to open doors for the wheelchair-bound in modelling, film and television, according to organisers. (Photo by Danish Siddiqui/Reuters)

Julian, left, is photographed by his mother with friend Gianluca, right, under water at a public pool in Gelsenkirchen, Germany, on a hot Friday, July 3, 2015. Germany faces a heat wave with temperatures up to 38 degrees Celsius (100 degrees Fahrenheit) at the weekend. (Photo by Martin Meissner/AP Photo)

The Mercedes-Benz F015 Luxury in Motion autonomous concept car is shown on stage during the 2015 International Consumer Electronics Show (CES) in Las Vegas, Nevada January 5, 2015. (Photo by Steve Marcus/Reuters)

Women pose for a picture at Havana city, Cuba, March 17, 2016. Obama arrives in Havana on Sunday for a historic visit that seals a rapprochement he and Cuban President Raul Castro agreed in December 2014 after 18 months of secret negotiations. (Photo by Ivan Alvarado/Reuters)

Miss Bahamas Celeste Marshall on stage at the 2012 Miss Universe National Costume Show on Friday, December 14, 2012 at PH Live in Las Vegas, Nevada. The 89 Miss Universe Contestants will compete for the Diamond Nexus Crown on December 19, 2012. (Photo by AP Photo/Miss Universe Organization L.P., LLLP)

January 22, 2017; Atlanta, GA, USA; Atlanta Falcons cheerleaders take a picture in the confetti after the game against the Green Bay Packers in the 2017 NFC Championship Game at the Georgia Dome. Atlanta defeated Green Bay 44-21. (Photo by Jason Getz/USA TODAY Sports)