集合（练习3）

package bao4;
import java.util.*;
public class Map
{
    public static void main(String[] args)
    {
        TreeMap<String,String> mm=new TreeMap<>();
        mm.put("001", "我");
        mm.put("002", "是");
        mm.put("003", "中");
        mm.put("004", "国");
        mm.put("005", "人");
        mm.put("006", "民");
        mm.remove("006");
        Set<String> keys=mm.keySet();
        for(String i:keys)
        {
            System.out.println(mm.get(i));
        }    
    }
}