矿工氡子体个人累积暴露量估算规范: estimation standards of personal cumulative exposure to radon decay products for miners
大气: 1.(地球周围的气体) atmosphere; air2.(呼吸; 沉重的呼吸) breath; heavy breathing 短语和例子跑得直喘大气 breathe heavily from running; 吓得连大气也不敢出 catch or hold one's breath in fear
