A street artist dances tango in Buenos Aires, Argentina, Tuesday, January 20, 2015. Tango is a partner dance that originated in the 1890's along the Rio de la Plata, the border between Uruguay and Argentina. UNESCO approved in 2009, a joint proposal by the two nations to include the dance in its Intangible Cultural Heritage List. (Photo by Rodrigo Abd/AP Photo)

A lunar eclipse appears behind a gargoyle atop the old red Dallas County Courthouse early Wednesday morning, October 8, 2014. The moon appears orange or red, the result of sunlight scattering off Earth's atmosphere. This is known as the blood moon. (Photo by Tom Fox/AP Photo/The Dallas Morning News)

A life-size robot named “Mark 1”, built by product and graphic designer Ricky Ma, 42, is seen in Hong Kong, China March 31, 2016. Ma, a robot enthusiast, spent a year-and-a half and more than HK$400,000 ($51,000) to create the humanoid robot, which is modelled after a Hollywood star, to fulfil his childhood dream. The eyes of the robot include face and color tracking functions. (Photo by Bobby Yip/Reuters)

Models pose on Harley-Davidson motorbikes during a media presentation of the 36th Bangkok International Motor Show in Bangkok March 24, 2015. The Bangkok International Motor Show will be held from March 25 to April 5. (Photo by Chaiwat Subprasom/Reuters)

A young Chinese girl kicks during a kung-fu class at Ritan Park on June 11, 2016 in Beijing, China. Ritan, meaning “sun altar”, is among the oldest parks in Beijing, built in the early 1500s during the Ming dynasty for the emperor to make sacrifices to the sun. (Photo by Kevin Frayer/Getty Images)

Activists attend a parade to demand rights of gender equality to LGBT community members in Santiago, Chile, November 25, 2017. (Photo by Ivan Alvarado/Reuters)

A cosplayer poses for a photograph during the Comic Market 90 (Comiket) event in Tokyo Big Sight on August 12, 2016, Tokyo, Japan. Many manga and anime fans wearing cosplay lined up in the sun for the first day of Comiket. Comiket was established in 1975 and focuses on manga, anime, gaming and cosplay. Organizers expect more than 500,000 visitors to attend this year's summer event which runs for three days until August 14. (Photo by Aflo/Splash News)

A man and a woman both wounded by what locals say was recent shelling by Ukrainian forces, react as they sit in an ambulance in Donetsk August 23, 2014. (Photo by Maxim Shemetov/Reuters)