I would say that they came to: our <span>estimate is that about three-quarters of the current annual incidence of breast-cancer in the United States is being caused by earlier ionizing radiation, primarily from medical sources. We will show that the recently growing incidence is not mysterious, and that if we wish to understand why the incidence has been growing, we must look to radiation events in the life of women 15-25-35-45 and more years before breast-cancer diagnosis. Moreover, there is recent evidence about induction of </span>early<span>-onset breast-cancer by radiation. there, i hope that this helps you. have a great day. =)</span>
Because the reason why airplane have closed windows is because we can't breathe in carbon dioxide when we go up. Of course there is oxygen just not a lot as we go up. Why would there be helium in the air? We would sound weird when we skydive.