Assertion: erbium | /r/HasProperty | important
Facets:
value: very
type: DEGREE
value: in the past decades
type: TEMPORAL
Source sentences:
text: Erbium, one of the rare-earth materials, has been very important in the development of optical communication technology in the past decades.
text: Erbium, one of the rare-earth materials, has been very important in the development of optical communication technology in the past decades.