Assertion: radio wave's frequency | /r/CapableOf | propagate by skywave
Facets:
value: at night
type: TEMPORAL
value: most efficiently
type: MANNER
Source sentences:
text: Frequencies below approximately 10 MHz (wavelengths longer than 30 meters), including broadcasts in the mediumwave and shortwave bands (and to some extent longwave), propagate most efficiently by skywave at night.