对除屏幕阅读器之外的所有设备都隐藏一个元素，该类只有.sr类。
您可以尝试运行以下代码以实现仅sr的Bootstrap-
<!DOCTYPE html> <html> <head> <title>Bootstrap Example</title> <link href = "/bootstrap/css/bootstrap.min.css" rel = "stylesheet"> <script src = "/scripts/jquery.min.js"></script> <script src = "/bootstrap/js/bootstrap.min.js"></script> </head> <body> <div class = "row" style = "padding: 91px 100px 19px 50px;"> <form class = "form-inline" role = "form"> <div class = "form-group"> <label class = "sr-only" for = "email">Email address</label> <input type = "email" class = "form-control" placeholder = "Enter email"> </div> <div class = "form-group"> <label class = "sr-only" for = "pass">Password</label> <input type = "password" class = "form-control" placeholder = "Password"> </div> </form> </div> </body> </html>