Compare the area of the folder papers with that of the roll. Do you find any increase in the area ? If so try to find out the reasons ?

Explanation

1. India.s three most polluted rivers are Ganga, Yamuna and Sutlej.
2. All these are flowing in northern India.
3. All are perennial and are originated in Himalayas.
4. The reasons for the highest pollution in Ganga are
a) industrial discharges from the factories on both banks of it.
b) disposal of household and other wastes
c) contamination by the fertilisers and pesticides applied in the surrounding agricultural fields. and
d) tens of, lakhs of devotees throng during Kumbha Melas pollute it.
5) The reasons for higher pollution in the Yamuna are
a) industrial discharges from Delhi and other places on the banks of it
b) disposal of household waste of `1(1)/(2)` crore odd Delhi population and other wastes and
c) contamination by the fertilisers and pesticides applied in the surrounding agricultural fields.
6. Sutlej, is the tributary, of Indus and it is also highly polluted river.
7. The reasons for its higher pollution levels are the causes discussed above.