Assertion: sulfur | /r/AtLocation | keratin
Facets:
Source sentences:
text: Sulfur is also present in keratin, which is necessary for the maintenance of the skin, hair, and nails, helping to give strength, shape, and hardness to these protein tissues.
text: Sulfur is present in keratin, which is a main structural component of the skin, hair, and nails.
text: Sulfur is also present in keratin, which is necessary for the maintenance of the skin, hair, and nails, helping to give strength, shape, and hardness to these protein tissues.