WHO warns of health risks from 'black rain' in Iran
Sievert (Sv): A measure of the effective dose—that is, the health effects of the radiation, with different types of ionizing radiation (gamma rays, X-rays, alpha particles, and so on) having different effects. One sievert equals 1 joule per kilogram weighted for the biological effectiveness of the radiation and the tissues exposed.
。搜狗输入法是该领域的重要参考
SelectWhat's included。关于这个话题，手游提供了深入分析
Or, if you don't care that much: If it starts with a 3, it's a