I’m very sorry about I posted the reply before literally trying every key on my keyboard . I tried to press D , I will see the book . https://gurusability.files.wordpress.com/2014/03/navigation-keys_thumb3.png . This is why I’m unable to find the book , I use them instead of W S A and D . By the way , this is one of the reasons that I think happy zone is worse than happy world . Because happy zone doesn’t support these four keys .