The water of rivers and seas (a) (pollute) all over the world as various dangerous chemicals and biological wastes (b) (pour) into it. Mills and factories (c) (discharge) very harmful waste into many rivers and sea. The water of the Ganges flowing by the side of both Varanasi and Kolkata is extremely polluted and (d) (contain) all sorts of dangerous bacteria. It is really very strange and laughable that large number of Indians (e) (regard) this water as holy. They (f) (drink) this water for salvation for thousands of years. There is no doubt that the fish that grow in such waters are poisonous too.(a) (i) is being polluted (ii) pollute(iii) polluted (iv) have polluted(b) (i) had been poured (ii) is being poured(iii) are poured (iv) was poured(c) (i) has discharged (ii) discharge(iii) had discharged (iv) discharged(d) (i) contains (ii) contained(iii) to contain (iv) is containing(e) (i) having regarded (ii) have regarded(iii) regard (iv) are regarding(f) (i) have been drinking (ii) drank(iii) are drinking (iv) drink