Instructions: Choose One Answer from Each Pair of Selections

Q44: One major way in which chlorofluorocarbons can

Q45: The legislation that empowers the U.S. Federal

Q46: Air becomes unhealthy when the air quality

Q47: PM-2.5 is more harmful than PM-10 because

Q48: Which substance is the most abundant primary

Q50: Pollution is most severe in urban areas

Q51: Which condition typically contributes to major air

Q52: Particles with diameters less than one micrometer

Q53: Describe how the use of a tall

Q54: Which toxic gas is an important component