对于Bootstrap模式中的表单，提交按钮应该放在哪里？

<form>
  <div class="form-group">
    <label for="exampleInputEmail">Email地址</label>
    <input type="email" class="form-control" id="exampleInputEmail" placeholder="请输入您的邮箱地址">
  </div>
  <div class="form-group">
    <label for="exampleInputPassword">密码</label>
    <input type="password" class="form-control" id="exampleInputPassword" placeholder="请输入密码">
  </div>
  
  <!-- 提交按钮 -->
  <div class="form-group">
    <button type="submit" class="btn btn-primary">提交</button>
  </div>
</form>