The arrival of African elephants at a Tucson zoo prompted a call for the zoo's fans to contribute leafy snacks. This file photo shows African elephants at the Pittsburgh Zoo & PPG Aquarium in 2011.
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Americans walk less than the citizens of any other industrialized nation, says Tom Vanderbilt. In this file photo from last summer, pedestrians and a cyclist cross the Brooklyn Bridge in New York City.
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A general view of the Radcliffe Camera building, part of the Bodleian Library, in Oxford, England. Along with the Vatican, the library is launching a project to digitally scan rare texts and put them online.
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State Attorney Angela Corey announces that George Zimmerman has been arrested and charged with second-degree murder in the shooting death of Trayvon Martin in Florida.
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