Can'；无法使用CSS下拉菜单找到问题

我已经看过了关于这个主题的所有问题，但没有发现我的编码有任何错误。我需要另一个人的眼睛来找出问题所在。一定有什么我只是没有看到，因为我已经成功地使下拉菜单之前

以下是我的菜单的html5编码：

<nav id="menu">
<ul>
    <li><a href="index.html" class="currentnew">Home</a></li>
    <li><a href="biography.html">Biography</a></li>
    <li><a href="artwork.html">Artwork</a></li>
        <ul>
            <li><a href="paintings.html">Paintings</a></li>
            <li><a href="drawings.html">Drawings</a></li>
            <li><a href="sculpture.html">Sculpture</a></li>
            <li><a href="viewall.html">View All</a></li>
        </ul>
    <li><a href="exhibitions.html">Exhibitions</a></li>
    <li><a href="commissions.html">Commissions</a></li>
</ul>
</nav>

---

在我认为你是有意之前，你关闭了一个

。看这里：

<li><a href="artwork.html">Artwork</a></li>
        <ul>
            <li><a href="paintings.html">Paintings</a></li>
            <li><a href="drawings.html">Drawings</a></li>
            <li><a href="sculpture.html">Sculpture</a></li>
            <li><a href="viewall.html">View All</a></li>
        </ul>

应该是：

<li>
        <a href="artwork.html">Artwork</a>
        <ul>
            <li><a href="paintings.html">Paintings</a></li>
            <li><a href="drawings.html">Drawings</a></li>
            <li><a href="sculpture.html">Sculpture</a></li>
            <li><a href="viewall.html">View All</a></li>
        </ul>
</li>

发生这种情况是因为

li:hover

应该启用

和
显示：阻止

试试这个：

<nav id="menu">
<ul>
   <li><a href="index.html" class="currentnew">Home</a></li>
   <li><a href="biography.html">Biography</a></li>
   <li><a href="artwork.html">Artwork</a>
       <ul>
           <li><a href="paintings.html">Paintings</a></li>
           <li><a href="drawings.html">Drawings</a></li>
           <li><a href="sculpture.html">Sculpture</a></li>
           <li><a href="viewall.html">View All</a></li>
       </ul>
   </li>
   <li><a href="exhibitions.html">Exhibitions</a></li>
   <li><a href="commissions.html">Commissions</a></li>
</ul>
</nav>

















示例：
你的ul是ul的孩子，它应该站在李的里面：）我就知道会是那样愚蠢的事情，非常感谢！：）
<nav id="menu">
<ul>
   <li><a href="index.html" class="currentnew">Home</a></li>
   <li><a href="biography.html">Biography</a></li>
   <li><a href="artwork.html">Artwork</a>
       <ul>
           <li><a href="paintings.html">Paintings</a></li>
           <li><a href="drawings.html">Drawings</a></li>
           <li><a href="sculpture.html">Sculpture</a></li>
           <li><a href="viewall.html">View All</a></li>
       </ul>
   </li>
   <li><a href="exhibitions.html">Exhibitions</a></li>
   <li><a href="commissions.html">Commissions</a></li>
</ul>
</nav>