也许是这样的：
<script>if(!window.jQuery){ var script = document.createElement('script'); script.type = "text/javascript"; script.src = "path/to/jQuery"; document.getElementsByTagName('head')[0].appendChild(script);}</script>
也许是这样的：
<script>if(!window.jQuery){ var script = document.createElement('script'); script.type = "text/javascript"; script.src = "path/to/jQuery"; document.getElementsByTagName('head')[0].appendChild(script);}</script>名师互学网 版权所有 (c)2021-2022 ICP备案号：晋ICP备2021003244-6号
