Compile-time binding

What is the output of the function main of Exercise 34, if the definition of small is replaced by the following definition:  (13)

class small

 public:    virtual void print() const;

    virtual int add()

 return x + y;

    small()

 

    small(int a, int b)

 x = a;

 y = b;

private:

    int x = 0;

    int y = 0;

;

What is the difference between compile-time binding and run-time binding? (12)

Is it legal to have an abstract class with all member functions pure virtual? (14)