英语翻译

问题描述:

英语翻译
How long does it take for a gril to grow their hairs?

首先,这句话有问题,前后单复数不一致.要么改为:How long does it take for a girl to grow her hairs?要么改为:How long does it take for girls to grow their hairs?
女孩需要多长时间头发才会长长?