How to make web service methods return string value in lines format?

My web service method looks like this

[WebMethod]
public string GetSomeLines()
{
  System.Text.StringBuilder builder = new StringBuilder();
  builder.AppendLine("Line1.");
  builder.AppendLine("Line2.");
  builder.AppendLine("Line3.");
  return builder.ToString();
}

But when I get the result from web browser or from delphi/c# consumer it will be like this:

Line1. Line2. Line3.

While I expect to see:

Line1.
Line2.
Line3.

I know may be returning a StringBuilder or String Array is an option here but I want to know if there is a way to make this with string result.

Thanks for your help.