我的Blade模板内容显示两次

I'm newbie in laravel. When I try to make master layout example, I get the content of my view printed out twice.

master.blade.php:

    <html>
    <head>
        <title>@yield('title')</title>
    </head>
    <body>
        @section('sidebar')
            This is the master sidebar.
        @show

        <div class="container">
            @yield('content')
        </div>
    </body>
</html>

page.blade.php:

@extends('layouts.master')

@section('title', 'Page Title')

@section('sidebar')


    <p>This is appended to the master sidebar.</p>
@endsection

@section('content')
    <p>This is my body content.</p>
@endsection

and my Route web.php:

Route::get('blade', function () {
    return view('page');
});

I trying use @stop intead of @endsection but it doesn't work.