<!DOCTYPE html>
<html>
<head>
<style>
body {
background-image: url("/i/photo/tree.png");
background-repeat: no-repeat;
}
</style>
</head>
<body>
<h1>Hello World!</h1>
<p>W3School 背景图像实例。</p>
<p>这幅背景图像仅显示一次，但它会打扰读者！</p>
</body>
</html>