Pollution can be controlled by

The concentration of dissolved oxygen in water for the growth of fish should be more than $X \ ppm$ and the Biochemical Oxygen Demand $(BOD)$ in clean water should be less than $Y \ ppm$. $X$ and $Y$ in $ppm$ are,respectively:

The smog which acts as an oxidizing agent is .....

How can domestic waste be used as manure?

The term 'Biosphere' refers to:

Explain the formation of photochemical smog with reactions.