Assertion: viper's fang | /r/HasProperty | folded
Facets:
Source sentences:
text: When the snake’s mouth is closed, the fangs are folded back and lie parallel to the roof of the mouth.
text: They have large fangs which can be folded back to allow the fish’s mouth to close.
text: The fangs are folded back against the roof of the mouth except when the snake strikes.