现有: import java.util.*; class AddStuff2 { public static void main(String [] args) { TreeSett=new TreeSet(); if (t.add("one")) if (t.add("two")) if (t.add ("three")) add("four"); for (String s : t) System.out.print (s); } } 结果为:()
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