Assertion: sponge | /r/ObjectUse | used by human
Facets:
value: for cleaning
type: PURPOSE
value: for centuries
type: TEMPORAL
Source sentences:
text: For centuries sponges have been used by humans.
text: Although they have been used by humans for cleaning, these days they are free to filter the water around them as nature intended.
text: Sponges that are composed of organic fibers (demosponges) have been used by humans for thousands of years for cleaning and other purposes.