How to remove line wrap to a new row C#?

From the server the answer comes in the form of a string.
For example:100
The length of the line I don't know, it all depends on the server response.
I need to reverse the change or to replace it with another symbol.
I tried that, but nothing happens:
str = str.Replace(Environment.NewLine, " ");
June 8th 19 at 17:05
1 answer
June 8th 19 at 17:07
It worked, thank you! - Kimberly.Ziemann57 commented on June 8th 19 at 17:10

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