Children play on a Nigerian oil-flow station in 2007. Nigeria, a major oil source for the United States, is riddled with ancient pipes and constant spills. That, plus the geopolitical challenges involved, is why much of Nigeria's crude is the kind of "tough oil" that author Michael Klare describes. George Osodi/AP hide caption

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Queen Latifah has won multiple acting and singing awards, including a Grammy for the song "U.N.I.T.Y." from her 1993 album, Black Reign. Bryan Bedder/Getty Images hide caption

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Most people already know Kurt Cobain the rock star. But author Karan Mahajan says Kurt Cobain the writer is "funny, self-aware, and snotty with a knack for off-the-cuff profundity." Frank Micelotta/Getty Images hide caption

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Women take part in a 1977 demonstration in New York City demanding safe and legal abortions for all women. Peter Keegan/Stringer/Hulton Archive/Getty Images hide caption

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Look twice: Champion skier and skateboarder Kevin Michael Connolly goes places most people wouldn't. And most people -- unlike Connolly -- have legs. Courtesy of Kevin Michael Connolly hide caption

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Dan Gottlieb hosts a mental-health call-in radio show on WHYY. In 1979, was in a near-fatal car accident that left him paralyzed from the chest down. hide caption

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