An internally displaced Afghan girl holds a child at a refugee camp in Kabul, Afghanistan May 31, 2016. (Photo by Mohammad Ismail/Reuters)

Afghan children play soccer in front of the war-damaged Darul Aman Palace in the suburbs of Kabul, Afghanistan, Wednesday, June 8, 2011. (Photo by Gemunu Amarasinghe/AP Photo)

This photo taken on October 8, 2017 shows dancers posing in formation to celebrate the upcoming Party Congress, in Rongan in China' s southern Guangxi region. China will convene its 19 th Party Congress on October 18, state media said, a key meeting held every five years where President Xi Jinping is expected to receive a second term as the ruling Communist Party' s top leader. (Photo by AFP Photo/Stringer)

Two zebras stand so close in Ngorongoro Crater, Tanzania. (Photo by Zhayynn James/Solent News)

A visitor poses for a picture during Sao Paulo Fashion Week in Sao Paulo, Brazil, March 16, 2017. (Photo by Nacho Doce/Reuters)

A man rides a horse at a playground on a hill in Kabul April 19, 2015. (Photo by Mohammad Ismail/Reuters)

Italy's Mount Etna, Europe's tallest and most active volcano, spews lava as it erupts on the southern island of Sicily, Italy, February 28, 2017. (Photo by Antonio Parrinello/Reuters)

A worker spreads paddy crop for drying in a rice mill complex on the outskirts of Ahmedabad February 3, 2011. (Photo by Amit Dave/Reuters)