多选题 Given the proper import(s), and given:
4. public static void main(String[] args) {
5. List＜Integer＞ x = new ArrayList＜Integer＞();
6. x.add(new Integer(3));
7. doStuff (x);
8. for(Integer i: x)
9. System.out.print (i + " ");
10. }
11. static void doStuff(List y) {
12. y.add(new Integer(4));
13. y.add(new Float(3.14f));
14. }
What is the result? (Choose all that apply.)