Assertion: rubber | /r/MadeOf | the sap of the rubber tree
Facets:
Source sentences:
text: Natural rubber is made from the sap of the rubber tree, which is extracted from the tree and then mixed with sulfur and white lead and heated in a process known as vulcanization.
text: Natural rubber is made from the sap of the rubber tree, which is extracted from the tree and then mixed with sulfur and white lead and heated in a process known as vulcanization.