HTML5里似乎有一组可以实现原生折叠隐藏的标签，不怎么常用，谁能提醒一下？

Question

就是一组标签，似乎需要嵌套使用，实在是想不起来，百度无果。。

Answer 1

是不是这个<details>标签和<summary>标签嵌套使用&nbsp;<summary>为<details>定义标题。标题可见，点击标题<summary>时，会显示出details的内容。open属性可以设置默认为显示<details&nbsp;open="open"> &nbsp;&nbsp;&nbsp;&nbsp;<summary>标题内容</summary> &nbsp;&nbsp;&nbsp;&nbsp;<div>折叠内容</div></details>

Answer 2

<select&nbsp;name=""&nbsp;id=""> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<option&nbsp;value="213221">3123213</option> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<option&nbsp;value="213221">3123213</option> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<option&nbsp;value="213221">3123213</option> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<option&nbsp;value="213221">3123213</option> &nbsp;&nbsp;&nbsp;&nbsp;</select>是这个嘛