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).