ASK WHERE { <http://dbpedia.org/resource/Lena_River> <http://dbpedia.org/ontology/mouthMountain> <http://dbpedia.org/resource/Laptev_Sea> }
Does the lena river flow into the Laptev Sea?
ASK WHERE { resource:Lena_River property:mouth_mountain resource:Laptev_Sea }
Yes
[Yes], Laptev Sea is the mouth location of Lena River.
[Yes], the Black Sea is the mouth of the river.
[Yes], Laptev Sea is  the mouth mountain of location.
[Yes], the Lithuanian Sea is the mouth of this place.