    Sentence 1: When did. Richard Dean  Adams make his inquiry?    Sentence 2: Based.on Teslo’s advice and  Westinghouse's demonstration that’ they]  could build a Complete AC system at the!  Columbian Exposition, a: - contract. - for!  building’ a two-phase AC. generating  system at the Niagara Falls. was awarded  to Westinghouse Electric.    * .