Define $BOD$.

Domestic waste primarily contains:

The addition of elements like nitrogen and phosphorus to a lake through streams leads to:

Thermal pollution of water bodies is due to

Which of the following is responsible for a sound level of $150 \, dB$ or more?

In agriculture,improper drainage of water leads to:
$I-$ The soil becomes waterlogged.
$II -$ The soil surface draws up salts from the water.
$III -$ Salts are deposited as a thin crust on the land surface.
$IV -$ Salts start accumulating around the roots of the plants.
$V -$ The increasing concentration of salts becomes favorable for crop growth.
$VI -$ It is highly beneficial for agriculture.
Which of the above statements are correct?