Young gymnasts practice pull-up on a bar at a gymnasium of a sports school in Jiaxing, Zhejiang province April 11, 2015. (Photo by William Hong/Reuters)

An Afghan man prepares tea for customers at a roadside tea shop on the outskirts of Jalalabad February 2, 2015. (Photo by Reuters/Parwiz)

Andrea Petkovic of Germany in action against Sara Errani of Italy during day one of the Mutua Madrid Open tennis tournament at the Caja Magica on May 3, 2014 in Madrid, Spain. (Photo by Julian Finney/Getty Images)

Syrians try to rescue a dead body under the debris of a collapsed building after Syrian and Russian army carried out an airstrike on opposition controlled residential area at Merce neighborhood of Aleppo, Syria on September 23, 2016. (Photo by Jawad al Rifai/Anadolu Agency/Getty Images)

Camp dwellers pump water from a well at Malkohi refugee camp in Jimeta, Adamawa State, Nigeria on February 19, 2019, four days ahead of the country's General elections set for February 23 after a last-minute rescheduling. Malkohi is a camp for internal displaced who fled their homes as Boko Haram insurgents advanced across north-eastern Nigeria. From their homes on the outskirts of Yola, capital of presidential candidate Atiku Abubakar's home state Adamawa, Malkohi residents say they feel forgotten. (Photo by Luis Tato/AFP Photo)

The moon is seen in its waxing gibbous stage as it rises behind the helicopter from the original Batman television show, which people can ride at the New Jersey State Fair, Saturday, June 22, 2013, in East Rutherford, N.J. The moon, which will reach its full stage on Sunday, is expected to be 13.5 percent closer to earth during a phenomenon known as supermoon. (Photo by Julio Cortez/AP Photo)

Female pilot Anna climbs out the cockpit of Japanese electronics company Suidobashi Heavy Industry's newly unveiled robot “Kuratas” at the Wonder Festival in Chiba, suburban Tokyo on July 29, 2012. The “Kuratas” robot, which will go on sale with a price tag of one million USD, measures four meters in height, weighs four tons and has four wheeled legs that can either be controlled remotely through the 3G network or by a human seated within the cockpit. (Photo by Yoshikazu Tsuno/AFP Photo)

Scores of internally displaced Muslims are at the heart of the humanitarian crisis in Central African Republic, where violence between Christians and Muslims has threatened to spiral into genocide. Photo: An internally displaced woman carries her child in a camp for internally displaced people (IDPs), located at Bangui International Airport, April 10, 2014. (Photo by Goran Tomasevic/Reuters)