How has DDT caused decline in bird population?</h2></div>

What are the sources of water pollution? What steps could be taken to prevent water pollution?</h2></div>

Producer gas is formed by passing over hot biomass.</h2></div>

Excess of carbon dioxide in the atmosphere leads to </h2></div>

_______ waste includes waste from labs, medical origin etc.</h2></div>

<span>Which of the following prevents afforestation in deserts?</span><br> </h2></div>

Carbon dioxide is called a "greenhouse" gas, because</h2></div>

"Some people say that city people do not create garbage. Cities are dirty because of slums". How do you feel a…