Android Admob响应错误

我的代码如下：

public class MainActivity extends Activity {
  mybutton b,b2;
  private AdView adView;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    b= (mybutton)findViewById(R.id.b);
    b.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        startActivity(new Intent(MainActivity.this, navdrawer.class));
      }
    });
    b2= (mybutton)findViewById(R.id.b2);
    b2.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            CopyReadAssets();
        }
    });


    // Create an ad.
    adView = new AdView(this);
    adView.setAdSize(AdSize.BANNER);
    adView.setAdUnitId("ca-app-pub-7080161350148208/1135515576");
    RelativeLayout layout = (RelativeLayout) findViewById(R.id.mainrelativel);
    layout.addView(adView);

    AdRequest adRequest = new AdRequest.Builder()
        .addTestDevice(AdRequest.DEVICE_ID_EMULATOR).build();

    // Start loading the ad in the background.
    adView.loadAd(adRequest);

  }


  //ads 3 methods
  /** Called when leaving the activity */
  @Override
  public void onPause() {
    if (adView != null) {
        adView.pause();
    }
    super.onPause();
}

/** Called when returning to the activity */
@Override
public void onResume() {
    super.onResume();
    if (adView != null) {
        adView.resume();
    }
  }

  /** Called before the activity is destroyed */
  @Override
  public void onDestroy() {
    if (adView != null) {
        adView.destroy();
    }
    super.onDestroy();
  }


  //pdf reader
  private void CopyReadAssets()
  {
    AssetManager assetManager = getAssets();

    InputStream in = null;
    OutputStream out = null;
    File file = new File(getFilesDir(), "cs.pdf");
    try
    {
        in = assetManager.open("cs.pdf");
        out = openFileOutput(file.getName(), Context.MODE_WORLD_READABLE);

        copyFile(in, out);
        in.close();
        in = null;
        out.flush();
        out.close();
        out = null;
    } catch (Exception e)
    {
        Log.e("tag", e.getMessage());
    }

    Intent intent = new Intent(Intent.ACTION_VIEW);
    intent.setDataAndType(
            Uri.parse("file://" + getFilesDir() + "/cs.pdf"),
            "application/pdf");

    startActivity(intent);
  }

  private void copyFile(InputStream in, OutputStream out) throws IOException
  {
    byte[] buffer = new byte[1024];
    int read;
    while ((read = in.read(buffer)) != -1)
    {
        out.write(buffer, 0, read);
    }
  }

  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
  }

  @Override
  public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
  }}
}

现在，我得到以下错误：

03-08 01:26:17.676 10523-10539/com.example.abc.yash1 W/Ads﹕ 有 获得广告回复时出现问题。错误代码：203-08 01:26:17.706 10523-10523/com.example.abc.yash1 W/Ads﹕ 无法加载广告：2