Former MF Global Holdings Ltd. Chairman and CEO Jon Corzine testified on Capitol Hill in December. On Wednesday, a former executive at the company refused to answer lawmakers' questions about events in the run-up to the firm's collapse. Susan Walsh/AP hide caption

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A driver pumps gas into his Toyota Prius hybrid at a gas station in Sunnyvale, Calif., in 2007. Paul Sakuma/AP hide caption

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Republican presidential candidate Rick Santorum addresses an election night party in Steubenville, Ohio, on Tuesday. Jim Watson/AFP/Getty Images hide caption

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People walk past the Bank of Greece headquarters in Athens. Greece toughened its stance to push creditors to accept a debt swap and take heavy losses, just one day before the Thursday deadline for completion of the deal to avert default. Louisa Gouliamaki/AFP/Getty Images hide caption

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A welder at Specialty Fab in North Lima, Ohio, works March 1 on a piece of a compressor skid frame that is bound for the Ohio Shale project. Manufacturing companies such as Specialty Fab could receive tax breaks if a proposal from the Obama administration goes through. Jim Watson/AFP/Getty Images hide caption

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Boeing employees work on a plane engine at the company's factory in Everett, Wash. The Obama administration's corporate tax cut proposal would offer even deeper cuts for U.S. manufacturers like Boeing. Stephen Brashear/Getty Images hide caption

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GOP presidential candidates (from left) Rick Santorum, Newt Gingrich, Mitt Romney and Ron Paul place their hands over their hearts during the national anthem at the start of a debate in Florida last month. Chip Somodevilla/Getty Images hide caption

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