A young man leaps across stellae at the Memorial to the Murdered Jews of Europe, also called the Holocaust Memorial, on January 26, 2012 in Berlin, Germany. (Photo by Sean Gallup/Getty Images)

These images of young children training were taken at a gymnastics summer camp in Bozhou, Anhui province, China on July 28, 2015. Children with promise are selected to attend, and their families hope training will not only benefit their children physically but also increase ‘willpower’, according to China News Service. (Photo by ChinaFotoPress/ChinaFotoPress via Getty Images)

Arnold Schwarzenegger gives a thumbs up as he arrives for the Europe premiere of his new movie 'Terminator: Genisys' in Berlin, Germany, Sunday, June 21, 2015. (AP Photo/Michael Sohn)

In this April 12, 2015 photo, Sayed Ahmed Abdoh poles his boat to check his fish traps in the Nile River, near Abu al-Nasr village, about 770 kilometers (480 miles) south of Cairo, Egypt. Abdoh caught some 20 fish this day and gave them to his friend, Salama Osman, a migrant worker in a Cairo apartment building, to celebrate his biannual return to their village. (Photo by Hiro Komae/AP Photo)

Venezuelan migrant and rap singer, Alfonso Mendoza aka “Alca”, 25, practice with his skateboard in a park in Barranquilla, Colombia on September 28, 2018. Alca -who arrived in Colombia nine months ago due to the crisis in his country- was born without legs and changed the wheelchair for a skateboard. At present, he is an example of overcoming adversity, practicing extreme sports, singing rap and giving conferences to young people in vulnerable situations. (Photo by Raul Arboleda/AFP Photo)

A Lockheed Super Constellation “Super Connie” lands during the Air14 airshow at the airport in Payerne August 30, 2014. The Swiss Air Force celebrates their 100th anniversary with the biggest airshow in Europe this year. (Photo by Ruben Sprich/Reuters)

Performers wait for delegations to arrive for traditional nomadic Naadam festival performance during the Asia-Europe Meeting (ASEM) summit just outside Ulaanbaatar, Mongolia, July 15, 2016. (Photo by Damir Sagolj/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)