我需要使用jquery在下拉列表中设置值

我需要设定“做研究”的价值

代码如下：

<div class="btn-group select bb-search-action-dropdown actionItem screen-block-z-index open">
    <button class="btn dropdown-toggle clearfix btn-info" data-toggle="dropdown"><span class="filter-option pull-left">Do research on</span>&nbsp;<span class="caret"></span>
    </button><span class="dropdown-arrow"></span>
    <ul class="dropdown-menu custom-icn custom-icn-anim" role="menu" style="max-height: 118px; overflow-y: auto; min-height: 96px;">
        <li rel="0" class=""><a tabindex="-1" href="#" class=""><span class="pull-left">I would like to</span></a>
        </li>
        <li rel="1" class="selected"><a tabindex="-1" href="#" class=""><span class="pull-left">Do research on</span></a>
        </li>
        <li rel="2"><a tabindex="-1" href="#" class=""><span class="pull-left"> Get a quote for</span></a>
        </li>
        <li rel="3"><a tabindex="-1" href="#" class=""><span class="pull-left">Check my eligibility for</span></a>
        </li>
        <li rel="4"><a tabindex="-1" href="#" class=""><span class="pull-left">Create an application</span></a>
        </li>
        <li rel="5"><a tabindex="-1" href="#" class=""><span class="pull-left">Talk to our help team</span></a>
        </li>
    </ul>
</div>

研究

以下是HTML：

<div class="btn-group select bb-search-action-dropdown actionItem screen-block-z-index open">
    <button id="drop" class="btn dropdown-toggle clearfix btn-info" data-toggle="dropdown"><span class="filter-option pull-left">Do research on</span>&nbsp;<span class="caret"></span>
    </button><span class="dropdown-arrow"></span>
    <ul class="dropdown-menu custom-icn custom-icn-anim" role="menu" style="max-height: 118px; overflow-y: auto; min-height: 96px;">
        <li rel="0" class=""><a tabindex="-1" href="#" class=""><span class="pull-left">I would like to</span></a>
        </li>
        <li rel="1" class="selected"><a tabindex="-1" href="#" class=""><span class="pull-left">Do research on</span></a>
        </li>
        <li rel="2"><a tabindex="-1" href="#" class=""><span class="pull-left"> Get a quote for</span></a>
        </li>
        <li rel="3"><a tabindex="-1" href="#" class=""><span class="pull-left">Check my eligibility for</span></a>
        </li>
        <li rel="4"><a tabindex="-1" href="#" class=""><span class="pull-left">Create an application</span></a>
        </li>
        <li rel="5"><a tabindex="-1" href="#" class=""><span class="pull-left">Talk to our help team</span></a>
        </li>
    </ul>
</div>

---

做研究，请不要把代码滴在评论。。。编辑问题本身以添加它们。还需要对您的问题进行更好的描述，并展示您试图解决的问题

\drop

是一个

。。。该标签上没有

值

$("#drop").val("Do Research On");