Assertion: narwhal's skin | /r/HasProperty | important source of vitamin c
Facets:
Source sentences:
text: The skin is an important source of vitamin C which is otherwise difficult to obtain.
text: Although the meat is used primarily for sled dogs, the skin is an important source of Vitamin C.
text: The skin is an important source of vitamin C which is otherwise difficult to obtain.
text: The skin is an important source of vitamin C which is otherwise difficult to obtain.