Which Substance Is Considered a Primary Pollutant

Q16: Instructions: Choose one answer from each pair

Q17: HFCs and HCFCs are _.<br>A) the primary

Q18: On clear, cold winter nights, cities tend

Q19: Instructions: Choose one answer from each pair

Q20: Photochemical smog _.<br>A) only forms at night<br>B)

Q22: Which gas is a major source of

Q23: Instructions: Choose one answer from each pair

Q24: Which pollutant is formed during the incomplete

Q25: Instructions: Choose one answer from each pair

Q26: In which area would air pollution typically