Simple List in Android

package thieu.mao.news;

import thieu.mao.utils.Variables;
import android.os.Bundle;
import android.app.Activity;
import android.app.ListActivity;
import android.view.Menu;
import android.widget.ArrayAdapter;

public class PaperActivity extends ListActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // setContentView(R.layout.paper);
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
                android.R.layout.simple_expandable_list_item_1, Variables.PAPER);
        // Variables.PAPER la 1 mang String
        setListAdapter(adapter);
    }

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

}