Solution for Pet free response question on 2004 AP Computer Science Exam - https://compsci.rocks/pet-solution/

Cat.java

public class Cat extends Pet {
  public Cat(String name) {
    super(name);
  }
  public String speak() {
    return "meow";
  }
}

Kennel.java

public void allSpeak() {
  for (Object o: petList) {
    Pet p = (Pet)o;
    p.speak(); 
  }
}

LoudDog.java

public class LoudDog extends Dog {
  public LoudDog(String name) {
    super(name);
  }
  public String speak() {
    return super.speak() + super.speak();
  }
}

Pet.java

public abstract class Pet {
  private String myName;
  public Pet(String name) {}
  public String getName() {}
  public abstract String speak();
}