The role of diesel in the U.S. economy, the factors driving up prices, and a controversial deal concerning the fuel are front-and-center today on The World from A to Z. Other topics include the history of the U.S. Navy on the 251st anniversary of its founding. We're remembering the extraordinary Chilean mine rescue of 2010. And we're looking at how animals are helping people with medical conditions. Plus: a re-enactment of the Battle of Hastings and icy "skiing" in London!