多选题 Given:
3. public class States {
4. static String s;
5. static Boolean b;
6. static Boolean t1() {return new Boolean("howdy");
7. static boolean t2() {return new Boolean(s); }
8. public static void main(String[] args) {
9. if(t1()) System.out.print("t1 ");
10. if(!t2()) System.out.print("t2 ");
11. if(t1() != t2()) System.out.print("!= ");
12. }
13. }
Which are true? (Choose all that apply.)