Why do they feel upset?

Shihab and Kaniz see that people are bathing, washing their clothes and throwing rubbish into the river water.

They see some polythene bags, plastics bottles and some other things floating on the river.

The lives of fishes are in danger bacause sometimes they get caught into polythene bags.

People throw kitchen rubbish into the water. They bath and wash clothes in the river. They also throw polythene bags, plastics bottles and some other things in the river water. Thus, the water is polluted

I do not wash clothes in the river water and I do not throw any sort of rubbish into it. Thus, 1 keep the water clean.