The purchase of utilities service by the United States, the state, the county, the city, the school board of the county, any governmental subdivisions of any of such governing bodies and any recognized church in this state for use exclusively for church purposes shall be exempt from the taxes levied under this article. The purchase of natural gas or fuel oil by a public or private utility, for resale or for use in the generation of electricity, or the purchase of fuel oil or kerosene for use as an aircraft engine fuel or propellant or for use in internal combustion engines is exempt from taxes levied under this article.