使用bootstrap时下拉菜单失效问题解决

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	<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@3.3.7/dist/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
	<script src="https://cdn.jsdelivr.net/npm/jquery@1.12.4/dist/jquery.min.js"></script>
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