Given a disfluent sentence, modify the sentence to it to its equivalent fluent form, preserving the meaning of the sentence.

Where no rather when was UNEP founded?
When was UNEP founded?

What keeps the sensitivity of hormones at the same level, oh I mean the immune system?
What keeps the sensitivity of the immune system at the same levels? 

When was Polish United Workers' no Berlin's first stock exchange established?
When was Berlin's first stock exchange established?