About: http://webisa.webdatacommons.org/455562288

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	But only in the last twenty years has the use of heroin, refined from opium, become a problem, especially in the cities.
http://www.w3.org/ns/prov#wasQuotedFrom	bbc.co.uk