PHP数组追加元素

 Array        (            [0] => 200kg            [1] => 200cm        )    [1] => Array        (            [0] => 20kg            [1] => 20cm            [2] => ok        )    [2] => Array        (            [0] => 2kg            [1] => 2cm            [2] => ko        )    [3] => Array        (            [0] => 1kg            [1] => 1cm            [2] => hello            [3] => world        ))