练习3：

public   class  MainTest {  
       
    public static void main(String args[]){
    	Bcycle b=new Bcycle();
    	b.print();
    }
    /**
     * 输出：
     * --Bcycle-------47
     * ----print-----47
     */
    
    public static void p(String str){};
}  

abstract class Cycle{
	public abstract void print();
}
class Bcycle extends Cycle{
	
	private int i=47;
	
	public Bcycle(){
		System.out.println("--Bcycle-------"+i);		
	}

	@Override
	public void print() {
		System.out.println("----print-----"+i);
	}
	
}