Question

acid deposition from primary pollutants falls where?
downwind
upwind
exactly below
far upwind

Explanation:

Primary pollutants are emitted directly from sources. Wind carries them. Acid deposition from primary pollutants falls downwind as the wind moves the pollutants in that direction. Upwind (against the wind direction) and far upwind would be areas the wind is coming from, not where the pollutants deposit. Exactly below is incorrect as wind disperses pollutants.

Answer:

downwind