在工作目录输入npm install bootstrap@4.0.0-alpha.6 --save
在HTML的head部分写入：
<!-- Required meta tags always come first -->
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<meta http-equiv:="x-ua-compatible" content="ie=edge">
<!-- Bootstrap CSS -->
<link rel="stylesheet" href="node_modules/bootstrap/dist/css/bootstrap.min.css">
在</body>前写入：
<!-- JQuery first, then Tether, then Bootstrap JS. -->
<script src="node_modules/jquery/dist/jquery.min.js"></script>
<script src="node_modules/tether/dist/js/tether.min.js"></script>
<script src="node_modules/bootstrap/dist/js/bootstrap.min.js"></script>
