試題詳解

9 The major culprits from transportation sources are carbon monoxide (CO), nitrogen oxides (NO and NOx), volatile organic compounds, sulfur dioxide, and hydrocarbons. These molecules react with sunlight, heat, ammonia, moisture, and other compounds to form the noxious vapors, ground level ozone, and particles that comprise ______.
(A) population
(B) smog
(C) toxicities
(D) malaria