Soviet Army soldiers sit on their tanks in front of the Czechoslovak Radio station building in central Prague during the first day of Soviet-led invasion to then Czechoslovakia on August 21, 1968. (Photo by Libor Hajsky/Reuters)

Canada's Mandy Marchak (R) is taken down by France's Pauline Biscarat during the final match of the Hong Kong Sevens rugby women's invitational cup in Hong Kong March 28, 2014. (Photo by Tyrone Siu/Reuters)

Residents cross over an improvised bridge after a landslide sent mud and water crashing onto homes close to the municipality of Salgar in Antioquia department, Colombia May 19, 2015. A landslide sent mud and water crashing onto homes in a town in Colombia's northwest mountains on Monday, killing at least 50 people and injuring dozens, officials said. (Photo by Jose Miguel Gomez/Reuters)

Barny, the Harveys Brewery dog has a sniff of a pint of beer at the Great British Beer Festival, at Olympia in London, Tuesday, August 11, 2015. The five day event is organised by the Campaign for Real Ale (CAMRA), with over 900 real ales, ciders, perries and international beers on offer. (Photo by Kirsty Wigglesworth/AP Photo)

Rabbits are seen in a cage, which is placed by authority as a test of the living conditions near the site of last week's blasts at Binhai new district in Tianjin, China, August 19, 2015. According to local media, the animals were alive after being placed near the blasts site for two hours. Four new fires have broken out at the site where two huge blasts last week killed 116 people, Chinese state media reported Friday soon after officials said safety hazards were found at almost 70 percent of firms handling dangerous chemicals in Beijing. (Photo by Reuters/Stringer)

Actress Laverne Cox attends The 59th GRAMMY Awards at STAPLES Center on February 12, 2017 in Los Angeles, California. (Photo by Christopher Polk/Getty Images for NARAS)

A woman has her hair done as people visit the International Beauty Show New York at Javits Center in New York, U.S., March 13, 2017. (Photo by Eduardo Munoz/Reuters)