重新排列数组键 php

我有这个数组：

Array
(
[15] =>     13.1

[16] =>     Mark one answer

[19] => You see a car on the hard shoulder of a motorway with a HELP pennant displayed. This means the driver is most likely to be

[20] => a disabled person first aid trained

[21] => a foreign visitor

[22] => a rescue patrol person

[25] => DES s15, HC r278);

如何让它从0排序键？得到这个：我知道有一个函数，但我的头被烧伤了，排序函数不符合我的需求，因为它们重新排列值，我需要它们被保存。

 Array
(
[0] =>  13.1

[1] =>  Mark one answer

[2] => You see a car on the hard shoulder of a motorway with a HELP pennant displayed. This means the driver is most likely to be

[3] => a disabled person first aid trained

[4] => a foreign visitor

[5] => a rescue patrol person

[6] => DES s15, HC r278);