Boys play with a ball in front of oilfields burned by Islamic State fighters in Qayyara, south of Mosul, Iraq November 23, 2016. (Photo by Goran Tomasevic/Reuters)

Members of the Iraqi Army fire towards Islamic State militant positions at the south of Mosul, Iraq December 10, 2016. (Photo by Alaa Al-Marjani/Reuters)

Common squirrel monkeys observe their Christmas present, a box full of mealworms, at the South America enclosure of the Budapest Zoo, in Budapest, Hungary, 24 December 2017. (Photo by Photo by Attila Kovacs/EPA/EFE/Rex Features/Shutterstock)

Participants play with water guns during the Sinchon Water Gun Festival in Seoul, South Korea, July 9, 2016. (Photo by Kim Hong-Ji/Reuters)

Tourists watch the sunrise and pray outside a church on the summit of Mount Moses, near the city of Saint Catherine, in the Sinai Peninsula, south of Egypt, December 9, 2015. (Photo by Amr Abdallah Dalsh/Reuters)

A model waits backstage before participating in AFI Joburg Fashion Week show with the theme #AfroAsia, in Johannesburg, South Africa October 4, 2018. Picture taken October 4, 2018. (Photo by Siphiwe Sibeko/Reuters)

An Exmoor wild goat silhouetted in the sky over the Bristol Channel at the valley of the Rocks, North Devon, as the UK's heat wave continues on July 19, 2018. (Photo by Paul Silver/South West News Service)

A person poses on the track during a fashion competition at the Durban July horse racing event in Durban, South Africa July 1, 2017. (Photo by Rogan Ward/Reuters)