Acoustic zoning is related to:

The first commercial pesticide was:

$A$: $Euro-II$ norms were framed to reduce the content of $CO$ and aromatic compounds from fuels.
$R$: These compounds lead to reduced visibility and carboxyhemoglobin formation.

What is the amount of oxygen consumed by bacteria to oxidize all the organic matter present in one liter of water called?

What is $BOD$?

In which one of the following have the $BOD$ (Biochemical Oxygen Demand) of sewage $(S)$,distillery effluent $(DE)$,paper mill effluent $(PE)$,and sugar mill effluent $(SE)$ been arranged in ascending order?