//父類
public?class?Telephone?{
	public?void?call(){};	
	public?void?message(){};		
}

//子類
public?class?Cellphone?extends?Telephone?{
	String?color?=?"black";		
	public?void?call()?{
		//?TODO?Auto-generated?method?stub
		System.out.println("用鍵盤打電話");
	}
	public?void?message()?{
		//?TODO?Auto-generated?method?stub
		System.out.println("用鍵盤發(fā)短信");
	}	
	public?void?clock(){
		System.out.println("有鬧鐘功能");
	}
}
//測(cè)試類
public?class?Initail?{
	public?static?void?main(String[]?args)?{	
		Cellphone?tel2?=?new?Cellphone();
		tel2.clock();
		System.out.println(tel2.color);
	}
}

所以，答案是可以。