A woman spits red paint as if it is blood protesting against bullfights in Madrid, Spain on March 27, 2016. Anti-bullfighting protesters have turn the iconic square of “Puerta del Sol” into a bullring. Protesters, almost naked covered with red paint as if it was blood, have demanded the abolition of bullfights under the slogan “The bull suffers!”. (Photo by Marcos del Mazo/Pacific Press)

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)

An artist shows her hands after working on a wall as part of a campaign to call for coexistence and the renouncement of violence through the painting of walls in Sanaa, Yemen March 15, 2015. (Photo by Mohamed al-Sayaghi/Reuters)

Shoppers wrestle over a television as they compete to purchase retail items on “Black Friday” at an Asda superstore in Wembley, north London November 28, 2014. Britain's high streets, malls and online sites were awash with discounts on Friday as more retailers than ever embraced U.S.-style “Black Friday” promotions, seeking to kickstart trading in the key Christmas period. In the United States the Friday following the Thanksgiving Day holiday is called Black Friday because spending usually surges and indicates the point at which American retailers begin to turn a profit for the year, or go “into the black”. (Photo by Luke MacGregor/Reuters)

Iraqi firefighters try to stop the fire of burning oil wells in Kirkuk, northern Iraq, 02 June 2016. Two Khabbaz oil field wells in Kirkuk Province, northern Iraq, exploded by suspected insurgents, a security official said. (Photo by EPA/Stringer)

Three Palestinian women sit on a beachfront as a wave comes rushing by in Gaza City on November 17, 2016. (Photo by Mohammed Abed/AFP Photo)

Zhao Deli waves as he pilots his self-made “flying scooter” in Dongguan, Guangdong Province, China, 12 August 2018 (issued 16 August 2018). Inspired by a cartoon he watched as a child, Zhao Deli sold off his apartment in pursuit of his dream of building a flying scooter. (Photo by Aleksandar Plavevski/EPA/EFE)

Ethnic Miao women in traditional costumes take part in a tug of war as they celebrate the local ethnic Miao's new year at a village in Rongshui Miao Autonomous county, Guangxi Zhuang Autonomous Region, China January 5, 2019. (Photo by Reuters/China Stringer Network)