Assertion: classical music's opera | /r/HasProperty | invented
Facets:
Source sentences:
text: This was happening by the beginning of the 17th century, which was the time when opera was invented.
text: It was also the time when opera was invented.
text: This was happening by the beginning of the 17th century, which was the time when opera was invented.
text: It was also the time when opera was invented.
text: This was happening by the beginning of the 17th century, which was the time when opera was invented.
text: It was also the time when opera was invented.