To comply with the oxygenate requirement, many gasoline producers have added MTBE to gasoline, although other additives produce similar improvements in air quality.
(other additives; produce; similar improvements in air quality) (many gasoline producers; have added; MTBE; to gasoline) Context(many gasoline producers have added,List([42, 76))):(many gasoline producers; have added MTBE to gasoline; )
many gasoline producers have added,List([42, 76))
other additives many gasoline producers many gasoline producers
produce have added have added MTBE to gasoline
similar improvements in air quality
MTBE to gasoline