非首位子元素选择器加号“+”的使用

li + li {
color: red;
}
img, span {
display: block;
}
img + span.caption {
font-style: italic;
color: red;
}
<ul>
<li>one</li> 这一行颜色不变
<li>one</li>
<li>two</li>
<li>three</li>
</ul>
<span class="caption">Before the photo</span>
<img src=“#”/>
<span class="caption">After first photo 1</span>
<span class="caption">After first photo 2</span>
<img src=“#”/>
<span class="caption">After The second photo</span>