About: http://webisa.webdatacommons.org/19476209

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	You can test if an opening is being used by stuffing the hole loosely with a paper towel and waiting to see if it gets pushed in or out.
http://www.w3.org/ns/prov#wasQuotedFrom	cor.net