the shiftIt took Amazon several years to overcome technical hurdles as it remade its voice assistant with new artificial intelligence technology.Alexa+ processes language in a more fluid way. Users can speak to it as they would to a human.Credit...Graham Dickie/The New York Timesthe shiftAlexa Got an A.I. Brain Transplant. How Smart Is It Now?It took Amazon several years to overcome technical hurdles as it remade its voice assistant with new artificial intelligence technology.Alexa+ processes la...