The SawStop saw can sense a slight electrical current that human fingers (and hot dogs) create. When it senses the current, the saw triggers a safety brake, which stops the blade in less than 5/1,000th of a second. Courtesy of SawStop hide caption

itoggle caption Courtesy of SawStop

At Expressway Toyota in Boston, co-owner Robert Boch says sales are rebounding thanks to loyal customers and big incentives such as zero percent financing. Chris Arnold/NPR hide caption

itoggle caption Chris Arnold/NPR

Contractors clean up lead paint at a contaminated building in Providence, R.I. Chitose Suzuki/AP hide caption

itoggle caption Chitose Suzuki/AP

The Boston Tea Party of 1773, as depicted in an old engraving. Bostonians dressed as Indians dumped 342 chests of tea overboard from three British ships in protest against "taxation without representation." The famous Tea Party took place at Griffin's Wharf, where the ships were tied up. The site remained a landmark even after the waterfront was filled in, leaving the spot several hundred yards inland. AP hide caption

itoggle caption AP

U.S. Federal Reserve Chairman Ben Bernanke testifying on Capitol Hill this month about how the U.S. economy still needs the assistance of the Fed. At the end of March, however, the agency plans to stop purchasing mortgage-backed securities. hide caption

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