现有: <br /> import java.util.*;     <br /> class AddStuff2  { <br /> public static void main(String  []  args)  {     <br /> TreeSet<string>t=new TreeSet<string>();     <br /> if (t.add("one"))     <br /> if (t.add("two"))    <br /> if (t.add ("three")) <br /> add("four"); <br /> for (String s  :  t)     <br /> System.out.print (s);    <br /> }     <br /> }     <br /> 结果为:()     </string></string>
A、 one
B、 one three two
C、 one two three
D、 one two three four
E、 four one three two
F、编译失败