下面程序的功能在监控台上每隔一秒钟显示一个字符串"Hello !" 。
public class Class31 implements Runnable
public static void main(String args[])
Class31 t=new Class31();
Thread tt=new Thread(t);
tt.start();
public void run()
for(;;)
try
______;
catch(______)
System. out. println("Hello");
参考答案:Thread.sleep(1000)
InterruptedException e