Two women look at a mobile phone as they stand on Tiananmen Square during a sand storm in heavily polluted weather in Beijing on February 28, 2013. Beijing residents were urged to stay indoors as pollution levels soared before a sandstorm brought further misery to China's capital. (Photo by Ed Jones/AFP Photo)

A visitor looks at a sculpture entitled “Couple Under an Umbrella, 2013” by artist Ron Mueck during the press day for his exhibition at the Fondation Cartier pour l'art contemporain in Paris April 15, 2013. (Photo by Charles Platiau/Reuters)

A tourist poses for a picture with the Sphinx at the Pyramids of Giza in Cairo, Egypt, on October 19, 2011. (Reuters/Jamal Saidi)

Models showcase Valentine's Day underwear celebrating the results of a recent survey revealing that men find the lingerie, boxer shorts and vests, the biggest turn on ahead of February 14 Valentine celebrations, at Waterloo on February 2, 2006 in London, England. (Photo by Gareth Cattermole/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)

Kevin Kvasnicka (L) and Jesse Gonzales openly carry firearms as they watch U.S. Republican presidential nominee Donald Trump speak on a big screen television along East 4th street during the Republican National Convention in Cleveland, Ohio, U.S., July 21, 2016. (Photo by Adrees Latif/Reuters)

Bride Fan Huixiang (front R), a 25-year-old cancer patient, receives flowers from nurses on her bed before her wedding ceremony at a hospital in Zhengzhou, Henan province November 17, 2014. Fan was diagnosed with late stage adenocarcinoma, a type of cancerous tumor, at her thoracic vertebra this June. She and her 24-year-old husband Yu Haining held their wedding ceremony at the hospital on Monday after five years of relationship, local media reported. (Photo by Reuters/China Daily)

Hundreds of Nigerians celebrate at an intersection in the flashpoint northern city of Kaduna on March 31, 2015 the victory of main opposition All Progressives Congress (APC) presidential candidate Mohammadu Buhari. (Photo by Nichole Sobecki/AFP Photo)