In java an abstract class cannot be sub-classed
? ? true
? ? false

False

Explanation:

An abstract class is a class declared abstract — it may or may not include abstract techniques. It is not possible to instantiate abstract classes, but they can be sub-classed.

Abstract method declaration

         abstract void moveTo(double X, double Y);

Usually the subclass offers solutions for all of the abstract techniques in its parent class when an abstract class is sub-classed. If not, however, the subclass must be declared abstract as well.

Example

public abstract class GraphicObject {

  // declaring fields

  // declaring non-abstract methods

  abstract void draw();

}