Assertion: cirrus | /r/HasProperty | visible
Facets:
value: at 20,000 feet
type: LOCATION
value: usually
type: DEGREE
value: clearly
type: DEGREE
Source sentences:
text: Cirrus clouds are usually visible at between 16,500 feet and 20,000 feet.
text: These cirrus clouds are very common and are usually clearly visible when the skies are clear.