Two young women, having enjoyed a drink at a party, dance together in Tehran, Iran. Although unrelated men and women are forbidden to socialise together many people ignore these strictures in the privacy of their own homes. (Photo by Hossein Fatemi/Reuters/Panos Pictures/Courtesy of World Press Photo Foundation)

Police officers clear the area near Borough market at London Bridge on June 3, 2017 in London, England. Police have responded to reports of a van hitting pedestrians on London Bridge in central London. (Photo by Dan Kitwood/Getty Images)

A woman dressed for la “La Diablada” festival walks down a road in Pillaro, Ecuador, Friday, January 6, 2017. Local legend holds that anyone who adopts a costume for the celebration and wears it at the event six years in a row will have good luck. (Photo by Dolores Ochoa/AP Photo)

Members of pop Idol SHINee and Super Junior carry the coffin containing the body of Jonghyun of SHINee during the funeral at the hospital on December 21, 2017 in Seoul, South Korea. The lead vocalist of the K-pop group was found dead, in what is believed to have been a suicide at his apartment on December 18. (Photo by Chung Sung-Jun/Getty Images)

Model friends Bella Hadid, Kendall Jenner, Stella Maxwell and actress Kristen Stewart and are seen having dinner together in Milan, Italy on June 16, 2018. Bella and Kendall cheekily showed the camera middle finger while couple Stella and Kristen talked. (Photo by Splash News and Pictures)

Protesting university students flee as police fire stun grenades outside Parliament in Cape Town, South Africa, Wednesday October 21, 2015. The protests are part of a wave of nationwide protests that have shut down many South Africa universities, which say they are struggling with higher operational costs as well as inadequate state subsidies. (Photo by AP Photo)

Situated 10km outside Nairobi city centre, this private giraffe sanctuary is centred around a colonial manor house named Giraffe Manor. Living within the grounds is a herd of rare Rothschild giraffe. The giraffes visit twice a day searching for food, before returning to the forest. Although still wild animals, they have become accustomed to receiving treats from residents and guests. (Photo by Klaus Thymann)

A citizen rides in smog on December 20, 2016 in Jinan, Shandong Province of China. Air quality index (AQI) readings exceeded 400 and some schools have suspended classes in Jinan. (Photo by VCG/VCG via Getty Images)