任务提问！
<!DOCTYPE HTML>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<p>1</p>
<p>2</p>
<p>3</p>
<p>4</p>
<p>5</p>
<p>6</p>
<p>7</p>
<script type="text/javascript">
var w= document.documentElement.offsetWidth
|| document.body.offsetWidth;
var h= document.documentElement.offsetHeight
|| document.body.offsetHeight;
document.write("w:"+w+"<br>");
document.write("h:"+h+"<br>");
</script>
</body>
</html>答案：
1
2
3
4
5
6
7
w:302
h:282
感觉尺寸这几节课讲的太抽象了！连个图片解释都没有！
