单section附录
附录只有一个section时
\appendix
\section*{Title of the Single appendix}
This is the first paragraph of the appendix ...
多section附录
如果附录有多个section，使用 \appendices 和 \section 即可。多section附录的示例代码及实际效果展示在下面。
% 附录有多个section时
\appendices
\section{Title of the 1nd appendix}
This is the first paragraph of Appx. A ...
\section{Title of the 2nd appendix}
This is the first paragraph of Appx. B ...
