Assertion: porcupine's quill | /r/HasProperty | coated
Facets:
value: in multiple layers of stiff keratin
type: OTHER
Source sentences:
text: All quills are hairs coated in multiple layers of stiff keratin.
text: However, their spines or quills are strong in structure as there are keratin-coated plates.
text: All quills are hairs coated in multiple layers of stiff keratin.