How is osmosis defined A- as active transport
B- as requiring a transport protein
C- as an example of facilitated diffusion
D- as diffusion of water through a selectively permeable membrane

significant amounts of nitrogen oxides, carbon monoxide, and other pollution

explanation:

passenger vehicles are a major pollution contributor, producing significant amounts of nitrogen oxides, carbon monoxide, and other pollution. in 2013, transportation contributed more than half of the carbon monoxide and nitrogen oxides, and almost a quarter of the hydrocarbons emitted into our air.