多选题 Given:
3. class MotorVehicle {
4. protected int doStuff(int x) {return x * 2; }
5. }
6. class Bicycle {
7. void go(MotorVehicle m) {
8. System.out.print(m. doStuff (21) + " ");
9. } }
10. public class Beemer extends MotorVehicle {
11. public static void main(String[] args) {
12. System.out.print(new Beemer().doStuff(11) + " ");
13. new Bicycle().go(new Beemer());
14. new Bicycle() .go(new MotorVehicle());
15. }
16. int doStuff(int x) {return x * 3; }
17. }
What is the result? (Choose all that apply.)