Two Tibetan women wearing traditional striped aprons, elaborate headdresses and abundant jewellery. Original Publication: From a photograph by Shephard. (Photo by Hulton Archive/Getty Images). Circa 1910

Two dogs sent into outer space by the Soviet Union after their safe return to earth. They spent 22 days in orbit. (Photo by Central Press/Getty Images). 22nd March 1966

Two chimpanzees share a piece of watermelon at Taronga Zoo on December 23, 2010 in Sydney, Australia. (Photo by Rick Stevens/Taronga Zoo via Getty Images)

Two children jumping through a water hydrant's shower on a New York street. They have come from a neighbouring co-educational playgroup organised by the city's Police Department. (Photo by Orlando/Getty Images). 1950

In this Sunday, June 27, 2010 file photo two men compete in an ostrich race at Highgate ostrich farm in Oudtshoorn, South Africa. Clambering onto an ostrich for a ride used to be popular among tourists in a South African town of Oudtshoorn known of as the “ostrich capital of the world”. Not so much anymore. Two major ostrich farms in Oudtshoorn have stopped offering ostrich rides to tourists, responding to concerns about the birds’ welfare. A third farm is sticking with the feature, saying it is regulated and that ostriches do not experience discomfort. The Highgate farm, however, continues to offer ostrich rides. (Photo by Shuji Kajiyama/AP Photo)

Sydney artist Phillip George poses with two surfboards of his own design at Marks Park, Tamarama on December 16, 2008 in Sydney, Australia. (Photo by Don Arnold/Getty Images)

James Castrission, “Cas” and Justin Jones “Jonesy” ski across an ice staking rink with two “You Can” patients on August 2, 2011 in Sydney, Australia. In 75 days, the Aussie adventure pair will attempt to cross 2,200 kilometres of Antarctic ice to the South Pole and back on foot to raise money for youth with cancer. The journey will require the two to trek with all the supplies for approximately three months of walking. Cas and Jonesy became the first to kayak unassisted over 3,300 kilometres from New Zealand to Australia in 2008. (Photo by Ryan Pierse/Getty Images)

An Iranian soldier guards two German tourists near the Iranian-Turkish border during World War II. Since the British occupation of Iran, all Axis nationals are being expelled from the country. (Photo by Three Lions/Getty Images). Circa 1941