Q1:

/* Missing statements ? */
public class NewTreeSet extends java.util.TreeSet
{
    public static void main(String [] args) 
    {
        java.util.TreeSet t = new java.util.TreeSet();
        t.clear();
    }
    public void clear() 
    {
        TreeMap m = new TreeMap();
        m.clear();
    }
}

which two statements, added independently at beginning of the program, allow the code to compile?

1. No statement is required
2. import java.util.*;
3. import.java.util.Tree*;
4. import java.util.TreeSet;
5. import java.util.TreeMap;