26. Which one of the following is not a cause for present global warming and climate change ?

1. 1. CFC emission

   
   
   

   2. Carbondioxide emission

   
   
   

   3. Deforstation

   
   
   

   4. Methane emission

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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27. DDT and BHC may act as

1. 1. allergens

   
   
   

   2. carcinogens

   
   
   

   3. asthematic agents

   
   
   

   4. none of these

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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28. Sulphur dioxide present in the industrial chimney exhaust causes

1. 1. respiratory and lung disease

   
   
   

   2. reduction in plant's productivity owing to acid rain

   
   
   

   3. corrosion building materials

   
   
   

   4. all of the above

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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29. Which of the following is not a natural source of air pollution ?

1. 1. Volcanic eruptions and lightening discharge

   
   
   

   2. Biological decay of vegetable matter

   
   
   

   3. Photochemical oxidation of organic number

   
   
   

   4. None of the above

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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30. Global warming may result in

1. 1. flood

   
   
   

   2. cuclone

   
   
   

   3. decrease in forest productivity

   
   
   

   4. all of the above

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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