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var
    i  : Integer;
    InFile : TStringList;
begin
  InFile := TStringList.Create;
  try
    InFile.LoadFromFile('c:\Hallo.txt'); // 4 Zeilen
    lblAnzahl.Caption:=IntToStr(InFile.Count);

  finally
    InFile.Free;
  end;					

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memo1.lines.clear;
memo1.lines.add(inFile.lines[3]);					

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memo1.lines.add(inFile.lines[3]);					

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memo1.lines.add(inFile.strings[3]);