5.1在(1)~(3)处填上适当的语句,使程序能正常运行。class MyThread implements Runable {(1) {while(true){System.out.print("hello");try { (2)//休眠1秒钟} catch (InterruptedException e) { e.printStackTrace(); }}}}public class Demo{public static void main(String []s){MyThread thread1= (3) //声明创建对象thread1Thread thread = new Thread(thread1,"线程1")thread.start(); //通过对象thread启动线程}}