How much percent of impurities are enough to make domestic sewage unfit for humans?

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

Solid waste increases with an increase in<span><br> </span></h2></div>

The worst enemy of ozone is</h2></div>

How burning of fossil fuels leads to increase in global warming?</h2></div>

Wastes may be sealed in concrete-filled drums and discharged to a depth of about 500 m. This specific statement is true …

Maximum ozone depletion is caused by</h2></div>

List any four effects of global warming.</h2></div>