A Philippine boy collects used plastic bottles to be sold at a junk shop at Divisoria market in Manila on November 29, 2017. (Photo by Noel Celis/AFP Photo)

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)

Dancers at the Windmill Theatre in London, England practice a routine wearing gas masks and hard-hats with their costumes, 1940. (Photo by Hulton Archive/Getty Images)

Andrey Karr from Western Riders Slacklines at sunset above big waves in Nazare, Portugal on December 27, 2017. (Photo by Aidan Williams/National Geographic Travel Photographer of the Year Contest)

A hyena kisses his own reflection while appearing to walk on water. (Photo by Jake De Wet/Caters News Agency)

Visitors are seen inside a newly opened bookstore in Chongqing, China on January 29, 2019. Covering an area of 1,400 square meters, the Zhongshuge Bookstore in Chongqing attracts readers with its creative decor. (Photo by Reuters/China Stringer Network)

A participant in the Crazy Races extreme sports game competes in the cross-country obstacle race in Ufa, Russia on September 21, 2015. (Photo by TASS/Barcroft Media)

A boy wearing a Lebanon's Hezbollah military outfit and carrying a toy gun walks during the funeral of three Hezbollah fighters who were killed while fighting alongside Syrian army forces in Syria in Nabatieh town, southern Lebanon, October 27, 2015. The fighters names are Hussein Hassan Shreifie, Ali al-Akbar Mohamad Khashfeh and Mohamad Saeed Fawaz. (Photo by Ali Hashisho/Reuters)