A competitor looses control of his pancake while racing during the Shrove Tuesday, or Mardi Gras, tradition at the National Cathedral February 21, 2012 in Washington, DC. (Photo by Chip Somodevilla/Getty Images)

South Korean teenagers participate in a warfare exercise as part of the Special Warfare Command's training course at a military base on August 4, 2011 in Seoul, South Korea. About 1,000 civilian volunteers including middle and high school students participated in the special force's four-day training programme to develop their spiritual and physical strength. (Photo by Chung Sung-Jun/Getty Images)

Technicians check a CRH high-speed train at Shanghai Hongqiao High-speed train base on December 28, 2011 in Shanghai, China. China's railway stations have started today to sell tickets for the 2012 Spring Festival travel season scheduled to run between January 8th and February 16th, centred around the Chinese New Year which this year falls on January 23rd. (Photo by ChinaFotoPress/Getty Images)

A traffic light is seen next to the Pink Supermoon in Frankfurt, Germany, April 8, 2020. (Photo by Kai Pfaffenbach/Reuters)

Youths play a traditional pillow fight game on a bamboo pole during festivities marking the 69th anniversary of Myanmar Independence Day on the outskirts of Yangon on January 4, 2017. Various traditional and local events were held on the holiday which marks the 69th anniversary of the country known before as Burma when British colonial rule ended on January 4, 1948. (Photo by Ye Aung Thu/AFP Photo)

Masked Guggen music bands parade through the streets on the occasion of the beginning of the Fasnacht Carnival of Lucerne, Switzerland, early 23 February 2017. (Photo by Urs Flueeler/EPA)

Former Soviet leader Mikhail Gorbachev attends the Gorby 80 Gala at the Royal Albert Hall on March 30, 2011 in London, England. The concert is to celebrate the 80th birthday of the former Soviet leader Mikhail Gorbachev.