Nouns		Verbs; phrasal verbs
·     composition		·     attribute
·     dizziness		·     break down into
·     droplet		·     contaminate
·     haze		·     decay
·     irritation		·     degrade
·     odor		·     emit
·     particle		·     fall back to
·     pollutant		·     muffle
·     smell		·     recycle
·     stream		·     obscure
		·     tend to be
Adjectives
·     entire		·     short-term
·     liquid		·     solid
·     long-term		·     temporary
Word combinations
·     acid rain		·     entire lifetime
·     a wide range of		·     motor vehicle
·     birth defect		·     reproductive rate
·     be sensitive to		·     sewer system
·     coal-fired power plant		·     take public transportation