<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>练习2</title>
<style type="text/css">
.ba:before {
content: "今天";
}
</style>
</head>
<body>
<div class=".ba">中午吃什么呢？</div>
</body>
</html>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Document</title>
<style>
.cc:before {
content: "今天";
}
</style>
</head>
<body>
<div class="cc">吃什么呢</div>
</body>
</html>
也不能放图片