how to make html select keep open

https://stackoverflow.com/questions/8430597/how-to-keep-select-dropdown-open-to-test-styles-on-option-in-firebug

让下拉框一直显示可以使用mutiple,然后调整hight就可以了

&lt;select class=&quot;select&quot; multiple=&quot;multiple&quot;&gt;
&lt;option selected&gt;Select&lt;/option&gt;
&lt;option&gt;Blue&lt;/option&gt;
&lt;option &gt;Red&lt;/option&gt;
&lt;option&gt;Green&lt;/option&gt;
&lt;option&gt;Yellow&lt;/option&gt;
&lt;option&gt;Brown&lt;/option&gt;
&lt;/select&gt;