翻译:Aparaffinbasecrudeisanoilwhosechiefcomponentsareparaffins,andwhichcompletelydistilled,leavesasolidresidueofwax.Anasphaltbasecrudeisanoilcomposedprimarilyofcycliccompounds(mostlynaphthenes)which,whendistilled,leavesasolidresidueofasphalt.Oilswhichfallinthemiddleofthesecategroriesareclassifiedasmixedbase.