Assertion: toucan's beak | /r/MadeOf | keratin
Facets:
Source sentences:
text: The inside of a beak is made of bone whereas the outer beak itself is actually made of Keratin.
text: The inside of a beak is made of bone whereas the outer beak itself is actually made of Keratin.
text: This chunky beak is made of keratin, the same substance that our nails and hair is made up of.