Black foot disease is caused by the toxicity of which of the following?

The accelerated aging of a lake by biological enrichment of its water is known as:

The major source of noise pollution,worldwide,is due to:

Give information about Eutrophication.

Impurities of water are

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.