1. A method for retrieving information spread across a plurality of different ontologies, comprising: defining a meta-ontology, wherein the meta-ontology includes high-level properties and their mappings to specific properties defined in a plurality of different ontologies; receiving a question, wherein the question is associated with a high-level property; and providing an answer to the question, wherein the answer is determined by referring only to the meta-ontology to retrieve required information, and in answering a question about a concept, synonyms of the concept's name used in the question are retrieved, and then, the synonyms are used to retrieve corresponding uniform resource identifiers, wherein a synonym is a high-level property included in a resource description framework description of each of the ontologies, wherein the resource description framework description of a first ontology of the ontologies describes how a first synonym corresponds to a first property from the first ontology and how the first synonym is queried such that the first synonym can be retrieved from the first ontology.