Q21. What is water pollution? Name any four major water pollutants.
Q22. What is global warming?
Q23. How do pesticides cause water pollution?
Q24. Write one source and one harmful effect of oxides of nitrogen.
Q25. Why hot water released by power plants and industries is considered a pollutant?
Q26. Clear, transparent water is always fit for drinking. Comment
Q27. How do industries cause water pollution?
Q28. Explain the differences between pure air and polluted air.
Q29. What is smog? How is it formed? What are its harmful effects?
Q30. Write any three ways of controlling water pollution.
Q31. Why does the increased level of nutrients in the water affect the survival of aquatic organisms?
Q32. Describe the ‘Green House Effect’ in your own words.