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来源：2-4 编程练习

慕UI4313976

2021-03-03 15:39:40

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>边框</title>
    <style>
        div{
            width: 150px;
            height: 150px;
            margin:10px;
        }
        /*补充代码*/
        div:nth-child(1){
            border: 3px dashed blue;
        }
        div:nth-child(2){
            border: 3px solid pink;
        }
        div:nth-child(3){
            border: 3px dotted green;
        }
    </style>
</head>
<body>
    <div class="box1">第一个div</div>
    <div class="box1">第二个div</div>
    <div class="box1">第三个div</div>
</body>
</html>