Londoners sleep on the platform and on the train tracks at Aldwych Underground station,London, during heavy all night Nazi bombing raids, October 8, 1940. (Photo by AP Photo)

A street performer jumps in the air inside Central Park as the colors of autumn become more prevalent in New York, October 29, 2015. (Photo by Lucas Jackson/Reuters)

With the entry of Poland into the European Union in 2004, Warsaw is currently experiencing the biggest economic boom of its history. The opening match of UEFA Euro 2012 is scheduled to take place in Warsaw. (Photo by: ryarwood; Source: Flickr)

1974: American boxer Muhammad Ali, formerly Cassius Clay, strikes an aggressive pose at a press conference on November 29, 1974. (Photo by Harry Dempster/Express/Getty Images); American actor Will Smith at the Royal Premiere of the film Ali in London on December 11, 2001. Smith starred as Muhammad Ali in the film. (Photo by Dave Hogan/Getty Images)

Costumed participants are reflected in a woman's sunglasses during the Summer Carnival Street Parade, which travels through the streets of the center of Rotterdam, the Netherlands, 27 July 2019. Twenty floats participated in the parade with dance acts and lots of music. (Photo by Marco De Swart/EPA/EFE/Rex Features/Shutterstock)

A participant in wingsuit flies above Tianmen Mountain at Zhangjiajie Scenic Spot during the 4th Red Bull WWL China Grand Prix on October 16, 2015 in Zhangjiajie, Hunan Province of China. The 4th Red Bull WWL China Grand Prix will last three days from October 16-18 in Zhangjiajie. (Photo by ChinaFotoPress/Getty Images)

A boy runs next to a portrait of Thailand's King Bhumibol Adulyadej, placed in celebration of the King's 88th birthday, in Bangkok, Thailand, December 5, 2015. (Photo by Jorge Silva/Reuters)

In this Monday, January 23, 2017 photo, chicken feet snacks shop owner Leung Kin-kung testes a chicken feet in Hong Kong. Saturday marks the start of the lunar Year of the Rooster and families in China will reunite for festivities, fireworks and food. While tradition calls for feasting on “auspicious” foods, many will also munch on staple snacks like “phoenix claws”, the Chinese name for chicken feet. (Photo by Vincent Yu/AP Photo)