FILE - In this May 27, 1997 file photo, workers walk in front of aircraft carrier "Varyag" at a dockyard in Mykolayiv, Ukraine. China officially acknowledged Wednesday, July 27, 2011, it is rebuilding the aircraft carrier it bought more than a decade ago, but said the refurbished ship will be used only for research and training. (AP Photo/Efrem Lukatsky, File)