问如何在flexbox中每行显示3个项目？

EN

<div class="serv">
  <ul>                                             
    @foreach(App\Http\Controllers\HomeController::getservice($service->id) as 
    $key => $value)
    <li>
      <span class="h3-service">{{$value->title}}</span>
      <p>{!!$value->description!!}</p>
    </li>
    @endforeach
  </ul>
</div>

.serv ul {
  display: inline-flex;
  margin: 0;
  padding: 0;
  width: 33%;
  text-align: left;
  float: left;
}
.serv ul li {
  list-style: none;
  display: inline-block;
  padding: 0;
}
.serv ul li span {
  padding: 0;
}