Assertion: tennis ball | /r/HasProperty | black
Facets:
value: incidentally
type: DEGREE
value: for nearly a century
type: TEMPORAL
value: originally
type: OTHER
Source sentences:
text: Originally, tennis balls were black or white, but the ITF introduced yellow tennis balls in the 1970s because the bright color made the balls more easy for television viewers to see.
text: For nearly a century, tennis balls were white or black.
text: Incidentally, tennis balls actually used to be black or white.