试试

<p><span class="mathquill-rendered-math" style="font-size:20px;"><span class="textarea"><textarea data-cke-editable="1" contenteditable="false"></textarea></span><span class="fraction non-leaf" mathquill-command-id="13"><span class="numerator" mathquill-block-id="14"><span mathquill-command-id="17">1</span></span><span class="denominator" mathquill-block-id="15"><span mathquill-command-id="18">2</span></span><span style="display:inline-block;width:0">&nbsp;</span></span></span><span>&nbsp;</span><br></p>