Freon gas causing stratospheric <span class="katex"><span class="katex-html" aria-hidden=&q…

What is organic farming?</h2></div>

On what does the harmful effect of pollution depend on?

Ozone layer of upper atmosphere is being destroyed by</h2></div>

The amount of biodegradable organic matter in sewage water can be estimated by measuring</h2></div>

Multiple Choice Questions<br> BOD is a measure of<br> </h2></div>

<span>Japan accident occurred in</span></h2></div>

If the river water is polluted with domestic sewage and garbage, it leads to the depletion of <br> </h…