A protest of the Keystone XL pipeline last March along its proposed route near Bradshaw, Nebraska. NH/AP hide caption

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"People like to share, if you give them the opportunity and the choice." — John Wilbanks James Duncan Davidson/TED hide caption

itoggle caption James Duncan Davidson/TED

A tasseled wobbegong shark (top) lies on the seafloor with the head of a brown-banded bamboo shark in its mouth on the fringing reef of Great Keppel Island on Australia's Great Barrier Reef in August 2011. Reuters/Landov hide caption

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Magellanic penguins strut their stuff on the rocky shoreline of Argentina's Punta Tombo, home to the largest colony of the birds in the world. Craig Lovell/Corbis hide caption

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Katherine Streeter for NPR

Charles, Prince of Wales, smells before tasting some ice cream during a visit to Gloucestershire. Maybe he was sniffing for fat? Barry Batchelor/Getty Images hide caption

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Some men take testosterone hoping to boost energy and libido, or to build strength. But at what risk? iStockphoto hide caption

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An artist's concept of a narrow asteroid belt orbiting a star similar to our own sun. NASA/JPL-Caltech hide caption

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Gas flaring near Highway 85 southwest of Williston. Analysts estimate that almost 30 percent of the gas being produced in the state is burned off. Jeff Brady/NPR hide caption

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Playing outside can help kids — and their parents — maintain a healthy weight. iStockphoto hide caption

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