Water and Air

the most urgent thing in this universe for human life is air only,with out oxgen our breath stops in secs,and not only for humanbeings foranimals, creatures also,i mean for entire lively hood which helps to live on this earth ,the second and most important as air is water ,but we can mange for some days with out water but it is also very precious becuse the total nervous sytem needs some minimum vitamins etc.. to motivate the nervous sytem intiallly to work,so in my view both are very urgent,but first is air and then water