对这个打印的结果有点不明白？

<code><?php class Animal{
    const age=1;
    public static $leg=4;
    public static function cry(){
        echo "1111";
    }
    public static function t1(){
        self::cry();
        echo self::age;
        echo self::$leg;
    }
    public static function t2(){
        self::cry();
        echo static::age;
        echo static::$leg;
    }
}
class human extends Animal{
    const age=30;
    public static $leg=2;
    public static function cry(){
        echo "5555";
    }
}
class man extends human{
    const age=16;
    public static $leg=1;
    public static function cry(){
        echo "aaaa";
    }
}

man::t2();
?></code>

<code><?php class Animal{
    const age=1;
    public static $leg=4;
    public static function cry(){
        echo "1111";
    }
    public static function t1(){
        self::cry();
        echo self::age;
        echo self::$leg;
    }
    public static function t2(){
        self::cry();
        echo static::age;
        echo static::$leg;
    }
}
class human extends Animal{
    const age=30;
    public static $leg=2;
    public static function cry(){
        echo "5555";
    }
}
class man extends human{
    const age=16;
    public static $leg=1;
    public static function cry(){
        echo "aaaa";
    }
}

man::t2();
?></code>