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, liters, 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, microorganisms, particles, dissolved, harmful).