Assertion: quicksand | /r/AtLocation | hollow
Facets:
value: usually
type: DEGREE
value: at the mouths of large rivers
type: LOCATION
Source sentences:
text: Quicksand is usually found in hollows at the mouths of large rivers or along flat stretches of streams or beaches where pools of water become partially filled with sand and an underlying layer of stiff clay or other dense material prevents drainage.