Air Pollutants Can Come from Both Natural Sources and Human

Q32: Particulate pollution with diameters less than 2.5

Q33: Ozone (O₃)forms naturally in the _ when

Q34: In which part of the United States

Q35: Sulfur dioxide (SO₂)can enter the atmosphere naturally

Q36: Sulfur-rich aerosols have the net effect of

Q38: The original Clean Air Act in the

Q39: In cities, during warm daylight hours, less

Q40: The urban heat island is _.<br>A)warmer air

Q41: A country breeze blows _.<br>A)from the city

Q42: The mixing layer is a _.<br>A)very stable