例：
<link rel="stylesheet" href="css/c1.css?v=1" type="text/css">
?v=1
https://stackoverflow.com/questions/1614429/what-is-style-cssver-1-tag
例：
<link rel="stylesheet" href="css/c1.css?v=1" type="text/css">
?v=1
https://stackoverflow.com/questions/1614429/what-is-style-cssver-1-tag
原文：https://www.cnblogs.com/vannn/p/8448965.html