[RESOLVIDO]R cannot be resolved to a variable

public class ListaVendasActivity extends Activity{
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.listar_vendas);
		
		
		SQLiteDatabase db = openOrCreateDatabase("vendas.db", Context.MODE_PRIVATE, null);
		
		ListView ltwvendas = (ListView) findViewById(R.id.ltwvendas);
		
		
		Cursor cursor = db.rawQuery("SELECT vendas._id, vendas.preco, vendas.la, vendas.lo,produtos.nome FROM vendas INNER JOIN produtos on produtos._id = vendas.produto ", null);
		
		String[] from = {"_id","preco","nome","la","lo"};
		int [] to = {R.id.txvid,R.id.txvpreco,R.id.txvnome,R.id.txvla, R.id.txvlo};
		
		//@SuppressWarnings("deprecation")
		SimpleCursorAdapter ad = new SimpleCursorAdapter(getBaseContext(),R.layout.model_listar, cursor, from, to);
		ltwvendas.setAdapter(ad);
		
		db.close();
		
	}


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

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="8" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
    <uses-permission android:name="android.permission.INTERNET"/>

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.vendas.Main"
            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="NovaVendaActivity"
            
            >
            
            
            
        </activity>
        
        
        <activity 
            android:name="ListaVendasActivity"
            
            >
            
            
            
        </activity>        
       
        
        
    </application>

</manifest>