\documentclass[a4paper,11pt]{letter}
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\usepackage{amsmath}
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\usepackage{url}
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\usepackage{indentfirst} %% POLSKIE AKAPITY
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\frenchspacing % francuskie zwyczaje typograficzne
\author{Robert Kmieć}
\date{\today~r.}
\signature{Robert Kmieć}
\address{Robert Kmieć\\ Wałowa 5 Street\\ 56-400 Oleśnica}
\begin{document}
\begin{letter}{Pr\"uftechnik Technology \\ Sułowska 43 Street\\51-180 Wrocław,
Poland}

\opening{Dear Sir~or Madam,}

I~am writing in response to Your advertisement about job opportunity.

I have just finished my studies (only a part of Master Thesis left). Now I
am looking for a job, where I could use and expand my technical skills and also
my soft skills (co-working, languages, talking with clients).\\

At first, I saw Yours job adverisements at \url{pracuj.pl} site, then I looked
for more informations about them on \url{pruftechnik-technology.pl} and I have
found them very challenging.

From my future employer, I am expecting stable employment, possibilities to
make new challenges (for example: learning new technologies, business trips,
meeting interesting people), solving engineering problems.

I am already able to hire.

%I~have always wanted to be a~part of OpenSource community, and I~hope 
%that Your company will help me, to become one.

%My engineer's thesis subject was \textit{``A package for teaching real-time
%systems using Linux Xenomai''}. During this project I~was working with
%embedded systems and developing kernel modules for ARM based boards.
%Now I~would like to expand my skills. I~am interested in new
%technologies. Creating and developing them is my passion. That is why
%I~would like to join Your team.

\closing{Yours faithfully,}

\encl{\begin{enumerate}
\item Curriculum Vitae
\end{enumerate}}
\end{letter}
\end{document}