A ballet dancer stretches backstage during Nacho Duato's “The Nutcracker” at the Mikhailovsky Theatre in St. Petersburg, Russia November 21, 2015. For theatregoers in St Petersburg, Nacho Duato's “The Nutcracker” demonstrates the global appeal of a Christmas classic. When the curtain rises at the Mikhailovsky Theatre, among the oldest opera and ballet houses in Russia, it's the culmination of hundreds of hours of toil and sweat by dancers, costume makers, set designers and musicians playing the famous score by Pyotr Tchaikovsky. (Photo by Grigory Dukor/Reuters)

An African Penguin holds a Valentine's Day card at the California Academy of Sciences on February 13, 2013 in San Francisco, California. In honor of Valentine's Day, the colony of African Penguins at the California Academy of Sciences received heart-shaped red valentines with hand written messages from Academy visitors. (Photo by Justin Sullivan)

Danny McWilliams, 56, is seen at his 36-foot-long replica of Walt Disney movie version of the Nautilus submarine from Jules Verne's “20,000 Leagues Under the Sea” at his rural home in Ellijay, Georgia, USA, 04 December 2013. (Photo by Erik S. Lesser/EPA)

Sara Takanashi of Japan, Maja Vtic from Slovenia and Germany's Carina Vogt (R-L) prepare for a training session of the women's Individual normal hill HS100 ski jumping at the Nordic World Ski Championships in Falun February 18, 2015. (Photo by Kai Pfaffenbach/Reuters)

Switzerland's lead Nicole Schwaegli (L) and second Marisa Winkelhausen sweep during their curling round robin game against Japan at the World Women's Curling Championships in Sapporo March 14, 2015. (Photo by Thomas Peter/Reuters)

An officer wipes sweat off the face of a Chinese People's Liberation Army (PLA) honor guard soldier as they rehearse for a welcoming ceremony for New Zealand's Governor-General Sir Jerry Mateparae at the Great Hall of the People in Beijing, Tuesday, July 21, 2015. (Photo by Mark Schiefelbein/AP Photo)

France's Alize Cornet celebrates scoring a point in the first round match of the French Open tennis tournament against Italy's Roberta Vinci at the Roland Garros stadium, in Paris, France, Monday, May 25, 2015. (Photo by Christophe Ena/AP Photo)

A man rides a horse through flames during the annual “Luminarias” celebration on the eve of Saint Anthony's day, Spain's patron saint of animals, in the village of San Bartolome de Pinares, northwest of Madrid, Spain, January 16, 2017. (Photo by Paul Hanna/Reuters)