Assertion: ballpoint pen's point | /r/HasProperty | an alloy of copper and zinc
Facets:
Source sentences:
text: The points of most ballpoint pens are made out of brass, which is an alloy of copper and zinc.
text: The points are made out of brass which is an alloy of copper and zinc.
text: The points of most ballpoint pens are made out of brass, an alloy of copper and zinc.