Assertion: manatee's membrane | /r/HasProperty | drawn across the eyeball
Facets:
value: for protection
type: PURPOSE
Source sentences:
text: They have a special membrane that can be drawn across the eyeball for protection.
text: The manatee has small eyes, protected by membranes which can be drawn across the eyeballs.
text: they even have a membrane that can be drawn across their eyeballs for protection.
text: Their eyes are small, and they have a nictitating membrane that can be drawn across the eyeball for protection.