\documentclass{article}
\usepackage{fontspec}
\usepackage{xeCJK}
\setCJKmainfont{Noto Sans CJK SC}

\begin{document}

\section{Introduction}

This is a test document for translation testing.
The quick brown fox jumps over the lazy dog.

\section{Technical Content}

Machine learning is a subset of artificial intelligence.
Neural networks are inspired by the human brain.

\subsection{Mathematical Formulas}

$E = mc^2$

$\int_0^\infty e^{-x^2} dx = \frac{\sqrt{\pi}}{2}$

\section{Conclusion}

This document is used for testing multilingual translation capabilities.

\end{document}