Android 安卓Admob:“；未能加载ad:0”；

我对新的admob有意见

    AdView mAdView = (AdView) findViewById(R.id.adView);
    AdRequest adRequest = new AdRequest.Builder().build();

    AdListener listener = new AdListener() {
        @Override
        public void onAdClosed() {
            super.onAdClosed();

            Log.i("AdListener", "onAdClosed");
        }
        @Override
        public void onAdFailedToLoad(int errorCode) {
            super.onAdFailedToLoad(errorCode);

            Log.i("AdListener", "onAdFailedToLoad---->"+errorCode);
        }
        @Override
        public void onAdLeftApplication() {
            super.onAdLeftApplication();

            Log.i("AdListener", "onAdLeftApplication");
        }
        @Override
        public void onAdLoaded() {
            super.onAdLoaded();

            Log.i("AdListener", "onAdLoaded");
        }
        @Override
        public void onAdOpened() {
            super.onAdOpened();

            Log.i("AdListener", "onAdOpened");
        }
    };
    mAdView.setAdListener(listener);
    mAdView.loadAd(adRequest);

应用程序->build.gradle

compile 'com.google.android.gms:play-services-analytics:9.6.1'
compile 'com.google.android.gms:play-services:9.6.1'
apply plugin: 'com.google.gms.google-services'

以下是我得到的：

W/Ads﹕ 获得广告回复时出现问题。错误代码：0 W/Ads﹕

未能加载广告：0