Single level Inheritance

When a class is derived from single base class and derived class can’t work as base class for another class called single level inheritance.
Example:

class A{
    public:
       void show(){
			cout<<"show";
       }
};
class B: public A{
   public:
		void display(){
			cout<<"display";
		}
};
void main(){
	B obj;
	obj.display();
	obj.show();
}