System.out.println(“error2”);

}

}

}

}

7．class GrandFather{

GrandFather(){System.out.println(“GrandFather”);}

}

class Book{

Book(){System.out.println(“Book”);}

}

class Father extends GrandFather{

Father(){System.out.println(“Father”);}

}

public class Son extends Father{

private Book b=new Book();

public Son(){System.out.println(“GrandFather”);}

public static void main(String args[]){

new Son();

}

8．class Count{

public static int counter=0;

public Count(){

counter++;

}

public int getCount(){

return counter;

}

}

public class StaticTest{

public static void main(String[]args){

Count[]c=new Count[5];

for(int i=0;i

c[i]=new Count();

System.out.println(c[i].getCount());

}

}

}

9．public class Calculation{

public float avg(int...nums){