Question

Fill in the blanks with the help of words given in bracket after
each sentence.
(a) When air is contaminated by ________ substances which have
a ________ effect on both the ________ and ________, it is referred
to as ________.
(air pollution, harmful, living, unwanted, non-living,
pollutants).
(b) Many ________ are responsible for causing ________ pollution.
Petroleum ________ are a major source of ________ pollutants
like ________ and ________.
(sulphur dioxide, refineries, industries, nitrogen dioxide,
gaseous, liquid, people, air).
(c) While ________ your teeth, leaving the ________ running may
waste several ________ of water.
(tap, litres, brushing, washing, drops)
(d) Water which is suitable for _________ is called ________ water.
(washing, bathing, drinking, potable, soft).
(e) Water which looks clean still has disease carrying ________
and ________ impurities.
(insects, microorganism, particles, dissolved, harmful)


NCERT Class VIII
Science - Exemplar Problems

Chapter 18. Pollution of Air and Water

Answer 1

(a) When air is contaminated by un wanted substances which have
a  harmful effect on both the living and nonliving, it is referred
to as air pollution.
(air pollution, harmful, living, unwanted, non-living,
pollutants).
(b) Many industries are responsible for causing air pollution.
Petroleum refineries are a major source of gaseous pollutants
like sulphur dioxide and nitrogen dioxide.
(sulphur dioxide, refineries, industries, nitrogen dioxide,
gaseous, liquid, people, air).
(c) While brushing your teeth, leaving the tap running may
waste several drops of water.
(tap, litres, brushing, washing, drops)
(d) Water which is suitable for bathing is called soft water.
(washing, bathing, drinking, potable, soft).
(e) Water which looks clean still has disease carrying microorganisms
and dissolved impurities.
(insects, microorganism, particles, dissolved, harmful)

Answer 2

answer in the attachment............

6fac5f4a45d8482411fa2e7f898555ee.rtf