跪求有关核辐射的英文文章，200字左右，非常感谢

【专家解说】：Nuclear radiation is not by definition evil rays that escape from nuclear energy reactors or nuclear bombs.Radiation is everywhere and some of it is beneficent。The sun's energy comes from nuclear fusion.Geothermal energy comes from the heat of radioactive rock deep down in the earth.And cosmic radiation constantly "bombards" the earth.Nuclear radiation is everywhere. Natural nuclear energy reactors have even been documented in Africa.Radiation is really nothing more than the emission of energy waves through space, as well as through physical objects.Usually these energy waves are electromagnetic radiation which are classified into：Radio waves、Infrared waves、Visible light、Ultraviolet waves、X-ray、Gamma rays and Cosmic rays。 Cosmic radiation can alter DNA in the cells in human and animal bodies.Nuclear radiation damages cells。