Assertion: pollution's cause | /r/HasProperty | mass-produced
Facets:
value: in the early 20th century
type: TEMPORAL
value: by henry ford
type: OTHER
value: in the u.s.
type: LOCATION
Source sentences:
text: Today, the leading cause of air pollution in the U.S. is motor vehicles, which were first mass-produced in the U.S. by Henry Ford in the early 20th century.