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)

An Omani woman prepares for a traditional dance during a ceremony attended by Britain's Prince Charles and his wife, Camilla, Duchess of Cornwall in Muscat, Oman, Saturday, November 5, 2016. The royal couple have started a three-nation royal tour of the Gulf in Oman. (Photo by Kamran Jebreili/AP Photo)

Guests enjoy a dinner at the table “Santa in the sky” lifted by a crane and elevated at 50 meters in the air and decorated to match the appearance of a “Santa Sleigh”, as part as the Christmas festivities in Brussels, Belgium, November 25, 2016. (Photo by Yves Herman/Reuters)

Female bodybuilders prepare to compete in the “Miss Bikini” category of the NABA/WFF Asia-Seoul Open Championship in Seoul on April 17, 2016. (Photo by Ed Jones/AFP Photo)

A woman and her dogs stop and look at a store mannequin wearing a dog's head mask outside a fashion shop in Nice, France, May 3, 2016. (Photo by Eric Gaillard/Reuters)

A participant holds his dog as colored powder is thrown into the air during the Color Run in Lausanne, Switzerland, 12 September 2015. The international 5km running event is inspired by the Hindu Holi spring festival of colors. (Photo by Valentin Flauraud/EPA)

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)

Winton Elementary fifth graders Juliana Ragan, from left, Chloe Windsor and Paisley Ganske wait backstage for their turn to perform as the Andrew Sisters during the Pearl Harbor/Veterans assembly at the school on Monday, December 7, 2015, in Coeur d'Alene, Idaho. Dec. 7 is the 74th anniversary of the Japanese bombing of Pearl Harbor. (Photo by Kathy Plonka/The Spokesman-Review via AP Photo)