{ "items" : [
    { "id" : "http://dbpedia.org/resource/Petrochemistry"
      "properties" : {
        "http://www.w3.org/2000/01/rdf-schema#comment" : [ "Petrochemistry is a branch of chemistry that studies the transformation of crude oil (petroleum) and natural gas into useful products or raw materials. These petrochemicals have become an essential part of the chemical industry today."] } } }
