Strontium- 90 can enter human body parts in place of<span><br> </span></h2></div>

Identify the harmful radiations emitted by the sun.</h2></div>

What is the process of re-growing a forest that once existed but was cut-down in the past called?

Which of the following conditions lead to formation of ozone?</h2></div>

Which of the following is the most dangerous environment hazard to mankind? </h2></div>

Draw a flow chart to show how deforestation leads to desertification. </h2></div>

<span>Metal generally present in polluted air is</span></h2></div>

The harmful and unwanted substances which degrade the quality of water are called as ________.</h2></d…