<span>Most fertile layer of soil is the ____.</span><br> </h2></div>

Which of the following is the effect of high BOD?

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

BOD is ___________ in polluted water and ________in potable water.</h2></div>

Green house effect is due to</h2></div>

What are the three main causes of water pollution?<br> <br> </h2></div>

<br> Planting of trees along road sides will reduce _________in the air .</h2></div>

The pollutant that causes hole in the ozone layer is<span><br> </span></h2></div>