如何让htlatex输出的displaymath保持代码不变而不是生成图片

Private Configuration Files
The leading entry, in the first list of options of the htlatex-like commands, can equal ‘html’ or ‘xhtml’. If this is not the case, the entry is assumed to be the name of a configuration file. The extension ‘cfg’ is assumed for names of configuration files that are listed without their extension.

A configuration file should take the following form for LaTeX files.

...early definitions...
\Preamble{options}
...definitions...
\begin{document}
...insertions into the header of the html file...
\EndPreamble
It is up to the user to decide the distribution of entries between the \Preamble and the htlatex-like commands.

Example The command ‘htlatex myfile "mycfg,2"’ requests the compilation of a file named myfile.tex, in the presence of a configuration file named mycfg.cfg. The configuration file might have the following content.
\Preamble{html}
\begin{document}
  \Css{body { color : red; }}
\EndPreamble