Three secondary schoolboys smoking an illicit cigarette in Hyde Park, London. (Photo by Evening Standard/Getty Images). May 1972

Australian actress Joy Smithers poses beside a poster featuring Australian cricketer Brett Lee during the official launch of the AceStar underwear range at Pink Salt on August 19, 2008 in Sydney, Australia. (Photo by Mike Flokis/Getty Images)

Handout picture released by Telam showing the tarmac of the Pedro Palacios Avenue in Ramos Mejia, province of Buenos Aires, Argentina, under which the channeled waters of the Maldonado stream flow, after it collapsed on April 8, 2014 leaving a 40-metre-long, 1.4-metre-deep hole. About 3000 people had to be evacuated in the Argentine provinces of Neuquen (soutwest), Catamarca (northwest), Santiago del estero (center) and Cordoba (center)due to the foods caused by heavy rain, official sources said. (Photo by Daniel Dabove/AFP Photo)

People appear dangling as a large-scale installation art piece by Leandro Erlich, named “Dalston House”, in London, England. Part of the “Beyond Barbican” summer series of events, the interactive installation is a full facade of a late nineteenth-century Victorian terraced house built on the ground with a large mirror above it to reflect people as to appear dangling from the structure. (Photo by Dan Dennison)

NASA astronaut Reid Wiseman and European Space Agency astronaut Alexander Gerst (not shown) works outside the space station's Quest airlock in the first of three spacewalks for the Expedition 41 crew aboard the International Space Station in this NASA image released October 8, 2014. (Photo by Reuters/NASA)

Four-year-old Rashida from Kobani, Syria, part of a new group of more than a thousand immigrants, sleeps as they wait at border line of Macedonia and Greece to enter into Macedonia near Gevgelija railway station August 20, 2015. (Photo by Ognen Teofilovski/Reuters)

A doctor performs surgery on an injured man with a part of an aluminium alloy fence through his chest after a car accident in Zhumadian, Henan province, China, September 15, 2014. The doctor managed to surgically remove the piece. (Photo by Reuters/Stringer)

A boy crawls under a cow during a religious ceremony celebrating the Tihar festival, also called Diwali, in Kathmandu, October 23, 2014. Hindus all over Nepal are celebrating the festival during which they worship cows, which are considered a maternal figure, and other animals. Also known as the festival of lights, devotees worship the goddess of wealth Laxmi by illuminating and decorating their homes using garlands, oil lamps, candles and colourful light bulbs. (Photo by Navesh Chitrakar/Reuters)