Assertion: aquifer | /r/HasAspect | water-filled caves
Facets:
value: within them
type: LOCATION
Source sentences:
text: With the exception of a few aquifers that have water-filled caves within them, aquifers are not underground lakes or holding tanks, but rather rock "sponges" that hold groundwater in tiny cracks, cavities, and pores (tiny openings in which a liquid can pass) between mineral grains (rocks are made of minerals).