Assertion : Organochlorine pesticides are organic compounds that have been chlorinated.
Reason : Fenitrothion is one of the organochlorine pesticides.

The main source of $BOD$ in the Ganga river is .....

Catalytic converters are fitted into automobiles to reduce the emission of poisonous gases. These converters use expensive metals as catalysts,which are:

Brewery and sugar factory waste alters the quality of a water body by increasing

The diagram below shows a scrubber. Identify $A, B, C$ and $D$.

Which of the following statements are correct regarding Eutrophication?
$I-$ Streams entering into a lake introduce nutrients like nitrogen and phosphorus,which encourage the growth of aquatic organisms.
$II-$ As the lake's fertility increases,plant and animal life flourish.
$III-$ Organic remains begin to deposit at the bottom of the lake.
$IV-$ Organic waste materials continue to accumulate in the lake.
$V -$ The lake becomes shallower and warmer.
$VI -$ Cold-water organisms are replaced by warm-water organisms.
$VII -$ Marsh plants take root in the shallows and begin to fill in the original lake basin.