Admob本机广告未在以下android 4.4设备中显示，但在android 5.0 plus设备中显示

我已经用低于Android 4.4的设备测试了该应用程序，中间广告正在显示，但本机广告没有显示，该应用程序在5.0 plus设备中显示中间广告和本机广告，运行良好

我希望代码能够很好地工作，因为android 5.0设备中显示的是本机广告，但在以下android 4.4设备中如何显示本机广告

我希望有人能帮助我

这是build.gradle

apply plugin: 'com.android.application'

android {
    compileSdkVersion 23
    buildToolsVersion "23.0.2"
    useLibrary 'org.apache.http.legacy'

    packagingOptions {
        exclude 'META-INF/DEPENDENCIES'
        exclude 'META-INF/NOTICE'
        exclude 'META-INF/LICENSE'
        exclude 'META-INF/LICENSE.txt'
        exclude 'META-INF/NOTICE.txt'
    }
    defaultConfig {
        applicationId "com.test.app"
        minSdkVersion 9
        targetSdkVersion 23
       // multiDexEnabled true
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
        }
    }
}

dependencies {
    compile files('libs/acra-4.5.0.jar')
    compile 'com.android.support:support-v4:23.1.1'
    compile 'com.android.support:appcompat-v7:23.1.1'
    compile 'com.google.code.gson:gson:1.6'
    compile 'com.google.android.gms:play-services-ads:9.2.1'
    //compile 'com.google.android.gms:play-services-identity:9.2.1'
    compile 'com.firebase:firebase-client-android:2.3.1'
    compile 'com.google.android.gms:play-services-gcm:9.2.1'
    //compile 'org.apache.httpcomponents:httpcore:4.4.1'
    //compile 'org.apache.httpcomponents:httpclient:4.5'
    compile 'com.google.android.gms:play-services-analytics:9.2.1'
}

这里是布局图

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:ads="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="53dp"
        android:background="#3F51B5"
        android:orientation="vertical">

        <ImageView
            ..

        <TextView
            ...

        <TextView
            android:layout_width="match_parent"
            android:layout_height="2dp"
            android:layout_alignParentBottom="true"
            android:background="#000000"
            android:text="" />
    </RelativeLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom"
        android:gravity="bottom"
        android:orientation="vertical">

        <com.google.android.gms.ads.AdView
            android:id="@+id/adView2"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            ads:adSize="SMART_BANNER"
            ads:adUnitId="@string/native_ad_unit_id" />
    </LinearLayout>

    <LinearLayout
        about listview ......

        <ListView
            android:id="@+id/lvMenu"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:divider="#ffffff"
            android:dividerHeight="2dp"
            android:minHeight="70dp" />
    </LinearLayout>

<!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
    </style>

    <style name="AppTheme.NoActionBar">
        <item name="windowActionBar">false</item>
        <item name="windowNoTitle">true</item>
    </style>

    <style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar" />

    <style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Light" />

</resources>

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.test.app"
    android:versionCode="1"
    android:versionName="1.1">

    <uses-sdk
        android:minSdkVersion="9"
        android:targetSdkVersion="23" />

    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
    <uses-permission android:name="android.permission.READ_PHONE_STATE" />

    <supports-screens
        android:anyDensity="true"
        android:largeScreens="true"
        android:normalScreens="true"
        android:requiresSmallestWidthDp="100"
        android:resizeable="true"
        android:smallScreens="true"
        android:xlargeScreens="true" />

    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

    <application
        android:name=".newApplication"
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@android:style/Theme.NoTitleBar.Fullscreen">
        <activity
            android:name=".SplachActivity"
            android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
         <activity
            android:name="com.google.android.gms.ads.AdActivity"
            android:configChanges="keyboard|keyboardHidden|orientation|screenLayout|uiMode|screenSize|smallestScreenSize"
            android:theme="@android:style/Theme.Translucent" />

        <meta-data
            android:name="com.google.android.gms.version"
            android:value="@integer/google_play_services_version" />


    </application>

</manifest>