单选题 1. public class SimpleCalc{ 2. public int value; 3. public void calculate(){value += 7;} 4. } And: 1. public class MultiCalc extends SimpleCalc{ 2. public void calculate(){value -= 3;} 3. public void calculate(int multiplier){ 4. calculate(); 5. super.calculate(); 6. value *= multiplier; 7. } 8. public static void main(String[] args){ 9. MultiCalc calculator = new MultiCalc(); 10. calculator.calculate(2); 11. System.out.println("Value is: " + calculator.value); 12. } 13. } What is the result