Assertion: ampulla's muscle | /r/CapableOf | force water
Facets:
value: back into the ampullae
type: TRANSITIVE-OBJECT
value: into the tube feet
type: TRANSITIVE-OBJECT
Source sentences:
text: Echinoderms move by alternately contracting muscles that force water into the tube feet, causing them to extend and push against the ground, then relaxing to allow the feet to retract.
text: Muscles are used to contract the tube feet and push the water back into the ampullae.