小弟我有有关问题

interface man{
    function talk();
}
abstract class person{
    abstract function name();
    abstract function age();
    var $c="这是一个抽象类
";
}
class xiaoming extends person implements man {
    function name(){
        echo ("xiaoming
");
    }
    function age(){
        echo ("12"."
");
    }
    function talk(){
        echo ("love
");
    }
}
class xiaoli extends person implements man{
    var $mingzi;
    function _construct($mingzi){
        $this->mingzi=$mingzi;
    }
    function name(){
        echo ($this->mingzi."
");
    }
    function age(){
        echo ("13
");
    }
    function talk(){
        echo ("you");
    }
}
$p = new xiaoming();

$p->name();
$p->age();
$p->talk();

$x = new xiaoli("xiaoli");
$x->age();
$x->name();
$x->talk();