Girls look at a penitent taking part in “Nuestro Senor Atado a la Columna, Maria Santisima de la Paz y San Juan Evangelista” Holy Week procession in Arcos de la Frontera, Spain, Tuesday, March 31, 2015. Hundreds of processions take place throughout Spain during the Easter Holy Week. (Photo by Daniel Ochoa de Olza/AP Photo)

“The Challenge!” Young boy relishes in a game of tug of war before school. Photo location: Lake Titicaca, Peru. (Photo and caption by Paul Heyman/National Geographic Photo Contest)

A man takes a selfie in front of a fire from oil that has been set ablaze in the Qayyarah area, some 60 kilometres (35 miles) south of Mosul, on October 19, 2016, during an operation by Iraqi forces against Islamic State (IS) group jihadists to retake the main hub city. In the biggest Iraqi military operation in years, forces have retaken dozens of villages, mostly south and east of Mosul, and are planning multiple assaults for October 20. (Photo by Yasin Akgul/AFP Photo)

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)

Marieke van der Meer from the Netherlands works on her sculpture “Flora” at the sand sculpture show in Binz on Ruegen island, Germany, 09 March 2016. With the motto “Fascination Nature”, 50 sand artists have created oversized sculptures. The sculptors use 16,000 tons of special sand that is pressed into big blocks first and then formed. The 7th sand sculpture show on 5,600 square meters of exhibition ground opens on 12 March 2016. (Photo by Ens Buettner/EPA)

A girl smiles as her hair is blown by a strong wind in the Chinatown area in Yokohama, near Tokyo, Friday, January 27, 2017. (Photo by Koji Sasahara/AP Photo)

Students training to be flight attendants hold books on their heads, chopsticks in their mouths, and papers in between their knees, as they take part in a standing posture practice at a vocational school in Shijiazhuang, Hebei province, China May 4, 2017. (Photo by Reuters/Stringer)

An Iraqi woman and foreigners use pair of compact discs as a filter to watch the partial solar eclipse in war-torn Baghdad, 29 March 2006. Without access to proper equipment to protect their eyes from the sun's rays, eclipse watchers in Iraq used makeshift filters. The moon blotted out the sun over northwest Africa early Wednesday, turning day into night in a total solar eclipse as it swept a shadowy path from the outer tip of Brazil to the steppes of Mongolia. (Photo by Hassan Ammar/AFP Photo)