Assertion: car | /r/Causes | air pollution
Facets:
Source sentences:
text: They can cause air pollution if too many are used in a small area like a city, and the combined pollution of the world's cars is thought to be partly to blame for climate change.
text: Cars can cause air pollution if too many are used in a small area like a city, and the combined pollution of the world's cars is partly to blame for climate change.