代码编辑器：
x
1
2
<meta charset="utf-8">3
<link href="/static/next/css/tryit.css?v=2017082407" rel="stylesheet"/> 4
<style> 5
p:nth-of-type(odd)6
{7
background:#ff0000;8
}9
p:nth-of-type(even)10
{11
background:#0000ff;12
}13
</style>14
15
<h1>This is a heading</h1>16
<p>The first paragraph.</p>17
<p>The second paragraph.</p>18
<p>The third paragraph.</p>