<select onchange="lxx(this)">
<option value="">全部</option>
<option value="水电" <c:if test='${lx=="水电"}'>selected=selected</c:if> >水电</option>
<option value="火电" <c:if test='${lx=="火电"}'>selected=selected</c:if>>火电</option>
<option value="风电" <c:if test='${lx=="风电"}'>selected=selected</c:if>>风电</option>
<option value="光伏" <c:if test='${lx=="光伏"}'>selected=selected</c:if>>光伏</option>
</select>