Question

<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> Mention two man-made and two natural sources of air pollution.

Answer 1

<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> Man-made sources of air pollution: Cutting down of trees and smoking
Natural sources of air pollution: Eruption of volcanoes and forest fires.