Question

_ should be avoided by building dams across the rivers

Answer 1

Answer:

plastic ,waste ,harmful colours etc

Answer 2

Hey mate!

I guess ur answer is "floods".

Explanation:

The main intention if building dams would be avoiding floods. so I think that 'floods' is the right answer.

(since it's in the context of geography...)

Hope this helps u...

Regards

@pavana Karanth