A Kurdish fighter from the People's Protection Units (YPG) fires his rifle at Islamic State militants as he runs across a street in Raqqa, Syria, July 2017. (Photo by Goran Tomasevic/Reuters)

LiLou the therapy pig stands in front of a departures board at San Francisco International Airport in San Francisco, California, U.S. October 4, 2019. (Photo by Jane Ross/Reuters)

Video bloggers stream live broadcast of an event to celebrate the fourth birthday of the world's only giant panda triplets, Meng Meng, Shuai Shuai and Ku Ku, at Chimelong Safari Park in Guangzhou, China July 29, 2018. (Photo by Bobby Yip/Reuters)

Comandos de Salvamento rescuers Maria Martinez (L) and Ana Chichilla attend to a wounded homeless man in San Salvador, El Salvador July 16, 2016. The man was attacked with a machete by suspected gang members. In 2015, El Salvador registered a record 103 homicides per 100,000 habitants, making it one of the most dangerous countries in the world outside a war zone. But for many young people who have few chances to distance themselves from rivalries between so-called maras in their schools and neighbourhoods, a civil-society organisation called the Comandos de Salvamento, or Rescue Corps, has been a refuge. (Photo by Jose Cabezas/Reuters)

A fellow officer comes to the aid of injured patrolman C.V. Satt, who was pelted with rocks and beer bottles during a clash between police and relief demonstrators in Denver September 23, 1935. (Photo by Henry G. Eisenhand/AP Photo)

Cars float up from a car garage in a mixture of storm water and gasoline in lower Manhattan as workers begin the process of pumping out the mess. (Photo by Carolyn Cole/Los Angeles Times/MCT)

A couple ride a motorcycle along a street during snow in Altay, Xinjiang Uighur Autonomous Region, China, November 8, 2015. Picture taken November 8, 2015. (Photo by Reuters/Stringer)

A journalist sits next to a dummy during a virtual Toyota test drive, during the press day at the 86th Geneva International Motor Show in Geneva, Switzerland, 01 March 2016. The Motor Show will open its gates to the public from 3th to 13th March presenting more than 200 exhibitors and more than 120 world and European premieres. (Photo by Martial Trezzini/EPA)