阅读下面程序 public cmass ThreadTest public static void main(String args[]) Thread t1=new Thread(new Hello()); Thread t2=new Thread(new Hello()); t1.start(); t2.start(); class Hello implements Runnable int i; public void run() while(true) System.out.println( Hello +i++); it(i==5) break; 此程序创建线程所使用的方法是
A.继承Thread类
B.实现Runnable接口
C.t1.start()
D.t2.start()