Who is the greatest enemy of nature and organism?</h2></div>

What are the agents that bring about such an undesirable change (pollution) are called?

World ozone day is celebrated on __________</h2></div>

What was the position of Delhi among the 41 most polluted cities of the world in the 1990s?

An effect of deforestation is</h2></div>

"Determination of biological oxygen demand (BOD) can help in suggesting the quality of a water body". Explain.…

Temperature variation in Pacific ocean in present time is called as</h2></div>

Maximum background radiation occurs in<span><br> </span></h2></div>