Assertion: oyster's shell | /r/HasProperty | closed by two adductor muscles
Facets:
value: actively
type: MANNER
Source sentences:
text: True clams, in the strict sense, are bivalves with equal shells closed by two adductor muscles situated at opposite ends of the shell, and with a powerful, muscular, burrowing foot.
text: The shell is actively closed using the adductor muscle or muscles which are attached to the inner surface of both valves.