Assertion: bear's mother | /r/CapableOf | contract the sphincter muscles
Facets:
value: to keep the joey
type: PURPOSE
value: at the opening of the pouch
type: LOCATION
Source sentences:
text: When safely in the pouch, it attaches its mouth to one of the mothers’ two breasts, and the mother contracts the sphincter muscles at the opening of the pouch to keep the joey secure.