https://w3id.org/framester/conceptnet5/data/en/poisonous_gas <https://w3id.org/framester/conceptnet5/schema/IsA> <https://w3id.org/framester/conceptnet5/data/en/gas> <https://w3id.org/framester/conceptnet5/data/en/product> <https://w3id.org/framester/conceptnet5/data/en/toxic_substance> risorse dalla linked data cloud