What amount of BOD indicates low water pollution?

Farming without the use of chemicals as fertilizers, herbicides and pesticides is known <span>as…

When harmful substances such as sewage, toxic chemicals get mixed with water, then:</h2></div>

Which one is not dangerous for life and atmosphere?<br> </h2></div>

All of the following are associated with organic farming except</h2></div>

Write name of any two green house gases.</h2></div>

Size of particulate matter ranges from ___.<span><br> </span></h2></div>

The ozone layer in earth's atmosphere is crucial for human survival because it<br> </h2></div>