Acoustic zoning is related to:

Exposure to a noise level of $............$ or more for a short period can damage the eardrums,leading to permanent hearing impairment. (in $,dB$)

Eutrophication of water bodies leading to the killing of fishes is mainly due to the non-availability of

$BOD$ of polluted water is estimated by measuring the amount of . . . . . . .

The 'Blue Baby' syndrome is caused by .........

In eutrophication,dissolved $O_2$ ....... and $BOD$ ......