How does deforestation lead to frequent floods and droughts? </h2></div>

Where are the catalytic converters fitted?

Which of the following does not contributes to greenhouse effect?</h2></div>

............ is a man-made source of air pollution.</h2></div>

What is air pollutions ? How does this pollution take place ?</h2></div>

Which of the following gases is regarded as an atmospheric pollutant?</h2></div>

What is the reason for choking of the surface off any pond or lake?

Sr-90 causes<span><br> </span></h2></div>