Cosmic radiation is proportional to altitude---the higher the altitude, the intenser the radiation is.And the more radiation one is exposed to, the higher the chance for him/her to get a cancer.

• 宇宙辐射随着高度增加而增加，离地球越远，受粒子的辐射越强，因此接受这种辐射最多，致癌危险越大。