Assertion: blackboard | /r/MadeOf | porcelain
Facets:
Source sentences:
text: Porcelain is very hard wearing and blackboards made of porcelain usually last 10–20 years in intensive use.
text: Porcelain is very hard wearing and blackboards made of porcelain usually last 10–20 years in intensive use.
text: Porcelain is very hard wearing and blackboards made of porcelain usually last 10–20 years in intensive use.