如何在Bootstrap 4中布局标签和值？

<div class="container">
  <div class="row">
    <div class="col-md-4">
      <label for="name">姓名：</label>
    </div>
    <div class="col-md-8">
      <input type="text" id="name" name="name">
    </div>
  </div>
  <div class="row">
    <div class="col-md-4">
      <label for="email">邮箱：</label>
    </div>
    <div class="col-md-8">
      <input type="email" id="email" name="email">
    </div>
  </div>
</div>

<div class="form-group">
  <label for="name">姓名：</label>
  <input type="text" class="form-control" id="name" name="name">
</div>
<div class="form-group">
  <label for="email">邮箱：</label>
  <input type="email" class="form-control" id="email" name="email">
</div>