Revelers dance at the Old Settler's Music Festival in Driftwood, Texas, U.S. on April 22, 2017. (Photo by Mohammad Khursheed/Reuters)

Musicians of the alphorn band "Holdersberger Alp- Traum- Blaeser" perform their skills on a raft floating on the Elbsee lake near Aitrang, southern Germany, on June 11, 2017. (Photo by Karl-Josef Hildenbrand/AFP Photo/DPA)

Children in a Hong Kong refugee resettlement area watch as former Vice President Richard Nixon shows them his badminton service. Nixon visited Hong Kong, April 4, 1964, during his tour of countries in the Far East. (Photo by AP Photo)

In this April 14, 2018 photo, National Ballet of Cuba dancer Daniela Gomez Perez stands on point as she poses outside the Capitol in Havana, Cuba. Gomez, who says Cubans love dancing, trusts the next generation of leaders will continue such traditions and that art will continue to be the engine of Cuban society. Gomez said she is proud to represent Cuba during a dance trip in May to Washington, Tampa and Chicago, and that the Cuban state has always supported dance. (Photo by Ramon Espinosa/AP Photo)

An artists performs on the street during a Myfest festival marking the May Day in the Kreuzberg district in Berlin, Germany on May 1, 2018. (Photo by Fabrizio Bensch/Reuters)

An OV-10 Bronco aircraft, decorated with World War One commemoration motifs, flies over Flanders international airport, ahead of the world's first Short Take Off & Landing competition on sand, in Wevelgem, Belgium May 8, 2018. (Photo by Francois Lenoir/Reuters)

Iraqi firefighters try to stop the fire of burning oil wells in Kirkuk, northern Iraq, 02 June 2016. Two Khabbaz oil field wells in Kirkuk Province, northern Iraq, exploded by suspected insurgents, a security official said. (Photo by EPA/Stringer)

Spectators pose for a selfie before the running of the Melbourne Cup at the Flemington Racecourse in Melbourne, Australia, Tuesday, November 6, 2018. (Photo by Andy Brownbill/AP Photo)