Jcreator4的问题？？
//filename: people_test.java

//定义people类
class   people{
public   people(){
height   =   0;
weight   =   0;
}
      public   double   height,weight;
      public   void   speak_hello(){
  System.out.println( "Hello! ");
      }
        public   void   average_height(){
        System.out.println(height);
        }
        public   void   average_weight(){
        System.out.println(weight);
        }
}

//定义China_people
class   China_people   extends   people{
public   void   China_gongfu(){
System.out.println( "坐如钟，站如松，睡如弓 ");
}
public   void   speak_hello(){
System.out.println( "你好，吃饭了吗 ");
}
public   void   average_height(){
this.height   =   173.0;
System.out.println( "中国人的平均身高: "+height+ "厘米 ");
}
public   void     average_weight(){
this.weight   =   67.34;
System.out.println( "中国人的平均体重: "+weight+ "公斤 ");
}
}

//定义American_people
class   American_people   extends   people{
public   void   American_boxing(){
System.out.println( "直拳、钩拳 ");
}
public   void   speak_hello(){
System.out.println( "How   do   you   do   ! ");
}
public   void   average_height(){
this.height   =   188.0;
System.out.println( "American   average   height:   "+height+ "   cm ");
}
public   void   average_weight(){
this.weight   =   80.23;
System.out.println( "American   average   weight:   "+weight+ "   kg ");
}
}

//定义Beijing_people
class   Beijing_people   extends   people{

public   void   Beijin_opera(){
System.out.println( "京剧术语 ");
}
public   void   speak_hello(){
System.out.println( "您好 ");
}
public   void   average_height(){
this.height   =   176.0;
System.out.println( "北京人的平均身高: "+height+ "厘米 ");
}
public   void   average_weight(){
this.weight   =   67.0;
System.out.println( "北京人的平均体重: "+weight+ "公斤 ");
}
}

//主类
public   class   people_test   {
        public   static   void   main(String[]   args)   {
                China_people   cp   =   new   China_people();
                American_people   ap   =   new   American_people();
                Beijing_people   bp   =   new   Beijing_people();
                cp.speak_hello();
                ap.speak_hello();
                bp.speak_hello();
                cp.average_height();
                ap.average_height();