ASK WHERE { <http://dbpedia.org/resource/Amazon_River> <http://dbpedia.org/property/sourceRegion> <http://dbpedia.org/resource/Arequipa_Region> }
Does the Amazon River start in Arequipa Region?
ASK WHERE { resource:Amazon_River property:source_region resource:Arequipa_Region }
Yes
[Yes], Arequipa Region is the source of Amazon River.
[Yes], the Arequipa region is the source of the Amazon.
[Yes], Arequipa Region is  the source region of location.
[Yes], the Arequipa region is the source region of the site.