Abstract Class:An abstract class is a class that contains at least one abstract method. The abstract method is function declaration without anybody and it has the only name of the method and its parameters.There can be any number of methods in the class and we have to declare the class as abstract only when there is an abstract method.An abstract class is a class that is only partially implemented by the programmer. It may contain one or more abstract methods. An abstract method is simply a function definition that serves to tell...