Define BOD. What is its significance in an aquatic ecosystem?</h2></div>

How is the value of COD compared to BOD?

How do automobiles fitted with catalytic converters reduce air pollution? Suggest the best fuel for such vehicles.</h…

<p><span>What is the single greatest source of solid waste?</span></p></h2></div>

Organic farming does not employ<br> </h2></div>

  <span>Which among the following is a major cause of water pollution?</span></h2>&l…

Ozone in the stratosphere is depleted by</h2></div>

Which of the following causes mutations at a very high rate?