If any nonconforming use (a) ceases for a continuous period of one year or more, or (b) is changed to or replaced by a conforming use, or (c) is moved for any distance for any reason, the land and building theretofore devoted to such non-conforming use shall thereupon be subject to all the regulations as to use for the district in which such land and building are located, as if such nonconforming use had never existed and shall be considered to have been abandoned.