LISBON, Sept 14 (AFP) - The United States has reserved a total of 20 air corridors across the Atlantic Ocean in the past 24 hours, some of them with access to Portugal's Lajes airbase on the Azores islands where an US air force unit is stationed, the Portuguese weekly Expresso reported Saturday. Quoting air controllers in the Azores, Expresso said that the United States normally only has four corridors. "There can only be one reason for this step, the transport of large quantities of light materiel that can only be transported by plane, as well as military personnel, to...