Inheritance

Which 2 statetments are true?

A: The extends keyword is used to specify inheritance
B: subclass of a non-abstract class cannot be declared abstract
C: subclass of an abstract class can be declared abstract
D: subclass of a final class cannot be abstract
E: A class, in which all the members are declared private, cannot be declared public.

Which of the following statements are true?
A: Subclasses must define all the abstract methods that the superclass defines.
B: A class implementing an interface must define all the methods of that interface
C: A class cannot override the super class's constructor
D: It is possible for two classes to be the superclass of each other
E: An interface can implement multiple interfaces

In which order are the following executed;
1. Static blocks of the base class
2. Static blocks of the class
3. Non-static blocks of the base class
4. Constructor of the base class
5. Non-static blocks of the class
6. Constructor of the class

What will the following code print when compiled and run?

class ABCD{
  int x = 10;
  static int y = 20;
}
class MNOP extends ABCD{
  int x = 30;
  static int y = 40;
}
public class TestClass {
  public static void main(String[] args) {
  System.out.println(new MNOP().x+", "+new   MNOP().y);
  }
}