Assertion: hedgehog's quill | /r/MadeOf | keratin
Facets:
Source sentences:
text: These quills are made of keratin, the same stuff our hair and fingernails are made of.
text: The quills are made of keratin, and are modified hairs
text: These quills are made of keratin, the same stuff our hair and fingernails are made of.
text: These quills are made of keratin, the same stuff our hair and fingernails are made of.