A polar bear fast asleep at London Zoo. (Photo by Fox Photos/Getty Images). 1961

Margaret Morris dancers exercising on the sands at Saint-Idesbald. (Photo by Fox Photos/Getty Images). August 1929

The world heavyweight boxing champion Joe Frazier, before his fight with Joe Bugner. (Photo by Evening Standard/Getty Images). 18th June 1973

Television actress Catherine Fuller visits Trafalgar Square in London and feeds the famous pigeons. (Photo by Harry Kerr/BIPs/Getty Images). 26th June 1956

A young boy adjusts his friend's Adolf Hitler mask during a game on a street in King's Cross, London. (Photo by William Vanderson/Getty Images). 1938

Participants wearing masks during a hazy day at the Beijing International Marathon in front of Tiananmen Square, in Beijing, October 19, 2014. (Photo by Reuters/Stringer)

Google's vice president Alan Eustace looks out of his spacesuit into the stratosphere prior to a record-breaking skydive over New Mexico, in this still image taken from video October 24, 2014, a handout courtesy of the Paragon Space Development Corporation. Eustace was lifted up 135,890 ft (41,420 metres) by an enormous balloon while wearing a specially designed pressurized space suit, the Paragon Space Development Corporation said. Eustace remained in a free fall for approximately 4.5 minutes before landing safely nearly 70 miles (43.4 kms) from his launch point, setting a world record for the highest skydive and breaking the sound barrier in the process. Eustace landed safely on the ground just 15 minutes after he was lifted into the air. (Photo by Reuters/Paragon Space Development Corporation)

A adorable bear cub cant get enough of playing buckaroo – as it hangs onto its mum splashing about in a river. His mum was attempting to catch a fish supper for the pair as the plucky cub continued to jump on her back. And as she was concentrating on her meal the young bear became a distraction. So she sprung into life with him on her back before he was tossed into the water much to his delight. (Photo by Lisa Sidorsky/Caters News)