Question: What chemical element does Canada export and import the most?
Answer(s):
answer: Gold

SPARQL query:
PREFIX ns: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?x
WHERE {
FILTER (?x != ns:m.0d060g)
FILTER (!isLiteral(?x) OR lang(?x) = '' OR langMatches(lang(?x), 'en'))
ns:m.0d060g ns:location.statistical_region.major_exports ?y .
?y ns:location.imports_exports_by_industry.industry ?x .
?x ns:kg.object_profile.prominent_type ns:chemistry.chemical_element . 
}