Assertion: cumulonimbus cloud's base | /r/HasProperty | 1–2 km
Facets:
value: above the ground
type: LOCATION
value: typically
type: DEGREE
Source sentences:
text: Lightning is usually produced by cumulonimbus clouds, which have bases that are typically 1–2 km (0.62–1.24 mi) above the ground and tops up to 15 km (9.3 mi) in height.