1.2

public class Test{

public static void main(String[] args){

int i;

for(i=1;i<=5;i++){

System.out.println("Welcome to java"); 

}

}

1.8

public class Test{

public static void main(String[]args){

        final double PI=3.14;

        double radius=5.5;

        System.out.println(2*radius*PI);

        System.out.println(PI*radius*radius);

       }

} 

1.12

public class AverageSpeed{

public static void main(String[]args){

double speedkm =60/(45.5/14);

double speedm = speedkm /1.6;

system.out.println（“averagespeed = ”+speedm + "m/h"）

}

}

public class Test{

public static viod main(String[ ] args){

System out println(" A");

System out println(" AA");

System out println("AAAAA");

System out println("A        A"); }

}