演示代码：
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<style type="text/css">
body{
font-size: 24px;
font-family: "微软雅黑";
color: #333333;
}
b{
font-weight: normal;
}
i{
font-style: normal;
}
</style>
</head>
<body>
<div>div我要自学1</div>
<p>p我要自学2</p>
<b>b我要自学3</b>
<strong>strong我要自学4</strong>
<i>i我要自学5</i>
<em>em我要自学6</em>
</body>
</html>
