AdMob广告未展示

因此，我使用Play Services SDK实施了AdMob广告。我已经“按书完成”所有操作，但广告不会展示。

如果我将AdView背景设置为白色，则会显示空白，但不会显示广告。我正在使用Fragments，但我将AdView放在了activity_main.xml（尽管在片段中，我在底部设置了60dp的边距）

这是我的onCreate代码（包含实际代码和“测试”代码）

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    final DrawerLayout drawer = (DrawerLayout)findViewById(R.id.drawer_layout);

    drawer.openDrawer(Gravity.LEFT);

    mNavigationDrawerFragment = (NavigationDrawerFragment)
            getFragmentManager().findFragmentById(R.id.navigation_drawer);
    mTitle = getTitle();

    // Set up the drawer.
    mNavigationDrawerFragment.setUp(
            R.id.navigation_drawer,
            (DrawerLayout) findViewById(R.id.drawer_layout));

    AdView adView = (AdView)this.findViewById(R.id.adView);
    AdRequest adRequest = new AdRequest.Builder()
            .addTestDevice(AdRequest.DEVICE_ID_EMULATOR)
            .addTestDevice("Device_ID")
            .build();
    adView.loadAd(adRequest);
}

这是我的 activity_main.xml

<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:ads="http://schemas.android.com/apk/res-auto"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.MainActivity">


<RelativeLayout
    android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_above="@+id/adView" >

    <com.google.android.gms.ads.AdView
        android:id="@+id/adView"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        ads:adUnitId="Unit_ID"
        ads:adSize="BANNER"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true" />
</RelativeLayout>

<fragment
    android:id="@+id/navigation_drawer"
    android:layout_width="@dimen/navigation_drawer_width"
    android:layout_height="match_parent"
    android:layout_gravity="start"
    android:name="com.NavigationDrawerFragment"
    tools:layout="@layout/fragment_navigation_drawer" />

我想念什么？