human
List all roads with optional geometry data.
gpt
```sparql
PREFIX :     <http://example.org/ontology#>
PREFIX geo:  <http://www.opengis.net/ont/geosparql#>
PREFIX rdf:  <http://www.w3.org/1999/02/22-rdf-syntax-ns#>

SELECT ?road ?geom
WHERE {
  ?road rdf:type :Road .
  OPTIONAL {
    ?road :hasGeometry ?geom .
  }
}
```