我正在尝试在Bootstrap 4中制作一个标签导航，当我加载页面时一切正常，但是一旦我离开主页按钮并尝试将其切换回正常工作状态

  

这是html导航标签代码

<div class="row justify-content-center">
  <ul class="nav nav-tabs col-md-8 justify-content-center" id="myTab" role="tablist">
    <li class="nav-item">
      <a class="nav-link active" id="home-tab" data-toggle="tab" href="#home" role="tab" aria-controls="home" aria-selected="true">Home</a>
    </li>
    <li class="nav-item">
      <a class="nav-link" id="profile-tab" data-toggle="tab" href="#profile" role="tab" aria-controls="profile" aria-selected="false">Profile</a>
    </li>
    <li class="nav-item">
      <a class="nav-link" id="contact-tab" data-toggle="tab" href="#contact" role="tab" aria-controls="contact" aria-selected="false">Contact</a>
    </li>
  </ul>
  <div class="tab-content col-md-8 mt-3" id="mycontent">
    <div class="tab-pane fade show active" id="home" role="tabpanel" aria-labelledby="home-tab">
      <div class="row">
        <div class="col-lg-4 col-md-12">
          <img src="img/nina-luong-IOwItPmnkyU-unsplash.jpg" class="img-fluid mb-3" alt="">
        </div>
        <div class="col-lg-4 col-md-12">
          <img src="img/nina-luong-IOwItPmnkyU-unsplash.jpg" class="img-fluid mb-3" alt="">
        </div>
        <div class="col-lg-4 col-md-12">
          <img src="img/nina-luong-IOwItPmnkyU-unsplash.jpg" class="img-fluid mb-3" alt="">
        </div>
      </div>
    </div>
    <div class="tab-pane fade" id="profile" role="tabpanel" aria-labelledby="profile-tab">
      <div class="row">
        <div class="col-lg-4 col-md-12">
          <img src="img/nina-luong-IOwItPmnkyU-unsplash.jpg" class="img-fluid mb-3" alt="">
        </div>
        <div class="col-lg-4 col-md-12">
          <img src="img/nina-luong-IOwItPmnkyU-unsplash.jpg" class="img-fluid mb-3" alt="">
        </div>

      </div>
    </div>
    <div class="tab-pane fade" id="contact" role="tabpanel" aria-labelledby="contact-tab">
      <div class="row">
        <div class="col-lg-4 col-md-12">
          <img src="img/nina-luong-IOwItPmnkyU-unsplash.jpg" class="img-fluid mb-3" alt="">
        </div>

      </div>
    </div>
  </div>
</div>

  

这是我的链接

     

脚本：

  <script type="text/javascript" src="js/jquery-3.4.1.min.js"></script>
  <script type="text/javascript" src="js/popper.min.js"></script>
  <script type="text/javascript" src="js/bootstrap.min.js"></script>
  <script type="text/javascript" src="js/mdb.min.js"></script>

  

css：

  <link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.8.2/css/all.css">
  <link href="css/bootstrap.min.css" rel="stylesheet">
  <link href="css/mdb.min.css" rel="stylesheet">
  <link href="css/style.css" rel="stylesheet">