如何在GET中发送表单并保持当前的url参数

I have a form select in blade file.

<form action="{{ Request::url() }}" method="get">
  <select name="year" id="year">
    <option value="2017">2017</option>
    <option value="2016">2016</option>
    <option value="2015">2015</option>
  </select>
  <input type="submit" value="Envoyer">
</form>

I need that when sending my form, the old parameters of the URL remain. I've url like that :

http://example.com/about-us?request=2d

But if I send my form, I've a URL like this :

http://example.com/about-us?year=2017

And I would like that

http://example.com/about-us?request=2d&year=2017

How can I do this in my blade file?

Thank you

You can add hidden input field:

<input type="hidden" name="request" value="{{ request('request') }}">