Assertion: mockingbird | /r/HasProperty | popular
Facets:
value: during early 1800s
type: TEMPORAL
value: as pets
type: MANNER
value: because of their beautiful singing
type: CAUSE
value: during the late 1700s
type: TEMPORAL
Source sentences:
text: During the late 1700s and early 1800s, mockingbirds were popular as pets because of their beautiful singing.