Visitors walk past "Sculpture #1" by Darren Bader at the Frieze Art Fair in London, Britain October 14, 2015. The Frieze Art Fair, which is one of the world's leading contemporary art fairs, opens today and runs through October 17. (Photo by Suzanne Plunkett/Reuters)

Dancers of the Czech National Ballet warm up backstage during a performance of “The Nutcracker – A Christmas Carol” at the National Theatre in Prague, Czech Republic, late 16 December 2017. Peter I. Tchaikovsky's “The Nutcracker”, one of his most famous compositions and seasonal ballets, premiered in St. Petersburg, Russia, on 18 December 1872, celebrates its 125th anniversary this year. (Photo by Martin Divisek/EPA/EFE)

A Citroen Ami One concept car sits on display during the media day of the Auto Shanghai 2019 motor show in Shanghai, China, 16 April 2019. The 18th Shanghai international automobile industry exhibition runs from 16 to 25 April. (Photo by Wu Hong/EPA/EFE)

Winner of the National Park Foundation's photo contest; Honorable Mention: Fan Favorite. Grand Canyon National Park, Arizona. Three friends enjoy sunrise over the Grand Canyon. (Photo by Peter Blanchard)

A three-seater Toyota Kikai concept car is displayed during the 2016 CES trade show in Las Vegas, Nevada January 8, 2016. (Photo by Steve Marcus/Reuters)

Bluebella Lingerie advertising photo shoot, Oxford Circus, London, Great Britain on September 14, 2017. Bluebella has staged its most daring lingerie campaign yet, sending 19 models to strut their stuff in skimp smalls on one of London's busiest junctions. Bluebella organised the show early in the morning to minimise congestion ahead of London Fashion Week which starts on Friday 15th September. The “models” included a medical PA, a company boss, four students, two actors, a musician and two writers. (Photo by Cavendish Press/LESAUVAGE/Bluebella)

An employee of the National Park Service takes a selfie with President Barack Obama, left, in the background meeting with the crowd after a tour of Everglades National Park on Earth Day, Wednesday, April 22, 2015, in Florida. Obama used the visit to warn of the damage that climate change is already inflicting on the nation's environmental treasures. (Photo by Lynne Sladky/AP Photo)

Demonstrators perform a dance in front of riot policemen during a march called by students to request changes in the education system in Santiago, Chile September 5, 2017. (Photo by Ivan Alvarado/Reuters)