Question: Among the rivers that have the United States of America as a basin country, which has the largest watershed area?
Choices: Ohio River
Amazon
Columbia River
Wisconsin
Danube
River Thames
Hudson River
Mississippi River
Missouri River
Rhine
SPARQL: SELECT ?e WHERE { ?e <pred:instance_of> ?c . ?c <pred:name> "river" . ?e <basin_country> ?e_1 . ?e_1 <pred:name> "United States of America" .  ?e <watershed_area> ?pv . ?pv <pred:value> ?v .  } ORDER BY DESC(?v) LIMIT 1
Program:
function: Find
inputs: United States of America
function: Relate
dependencies: 0
inputs: basin country
backward
function: FilterConcept
dependencies: 1
inputs: river
function: SelectAmong
dependencies: 2
inputs: watershed area
largest
Answer: Mississippi River