A young woman wearing no trousers hits the ski slopes at a ski resort in Xuzhou, in east China's Jiangsu province on January 13, 2015 in a promotional effort to equal “No Pants Subway Ride”, which was marked on January 11 this year. The promotional “No Pants Subway Ride” stunt on January 11 was held as commuters in some 60 cities around the world braved public transportation in their undies, which has gone global since its first staging by US group Improv Everywhere in New York in 2002. (Photo by AFP Photo)

“Cossacks are a group of predominantly East Slavic people who originally were members of democratic, semi-military communities in Ukraine and Southern Russia. They inhabited sparsely populated areas and islands in the lower Dnieper and Don basins, and played an important role in the historical development of both Ukraine and Russia”. – Wikipedia

Photo: Кубанский казачий хор (Kuban Cossack chorus) - Розпрягайте, хлопцi, коней (Unharness The Horses, Guys!) – Ukrainian

Gerald Herbert is a staff photographer for the AP based in New Orleans, Louisiana. Before that he was a staff photographer for the Washington Times, the New York Daily News and a freelancer for the AP in New Orleans, Boston and New York. Photo: A worker grooms away tracks after an alligator crossed through a sand trap on the 14th hole during the first round of the PGA Tour Zurich Classic golf tournament at TPC Louisiana in Avondale, La., Thursday, April 25, 2013. (Photo by Gerald Herbert/AP Photo)

Palestinian boy Mohammad al-Bana, 10, sells mints at a market in Gaza City March 29, 2016. Bana, whose father is unemployed, earns around 10 Shekels ($2.5) per day. The boy starts working after finishing school. He hopes to continue education and become an engineer in the future. (Photo by Mohammed Salem/Reuters)

Bob Woodward looks at the reconstruction he built of the Orpheus Pavement at Prinknash Abbey on March 31, 2010 in Gloucester, England. The replica mosiac, made of more than one-and-a-half million pieces of stone is described as one of the most significant archaeological projects of recent times. (Photo by Matt Cardy/Getty Images)

A cloud of black smoke billows out the exhaust pipe of John Robertson's diesel dragster as he runs down the track during the 2015 NHRA Kansas Nationals, Friday, May 22, 2015, at Heartland Park in Topeka, Kan. (Photo by Chris Neal/The Topeka Capital-Journal via AP Photo)

O Santa Claus of Australia competes in the mens 80–84 years 100 metres heats during day two of the 2009 Sydney World Masters Games at Sydney Olympic Park on October 11, 2009 in Sydney, Australia. (Photo by Mark Nolan/Getty Images)

Google has built its first self-driving car prototypes and hopes to test hundreds more models this summer. If all goes well, the company is planning a pilot program in California over the next few years.