The depletion of the ozone layer in the stratosphere is responsible for which of the following?

$BOD$ value of water is $20 \ ppm$. Then what can you conclude regarding water?

The gaseous envelope around the earth is known as the atmosphere. The lowest layer of this extends up to $10 \ km$ from sea level; this layer is $.......$

What are biodegradable and non-biodegradable pollutants?

In an agricultural field,which among the following is the highest producer of methane?

How can domestic waste be used as manure?