用10Ci的铱192放射源在野外对距其1m处厚20mm的钢进行透照拍片,已知该射源的电离常数为0.6rhm/Ci,对钢的半值层为10mm,为了获得2.0黑度的底片需要曝光()。 ["10min","20min","30min","40min"]
“昏、墨、贼、杀”中的刑名是() ["昏","墨","贼","杀"]
腰脊不举见于《素问•痿论》中痿证的() ["A、骨痿","B、痿躄","C、脉痿","D、筋痿","E、肉痿"]
“天下皆知美之为美,斯恶矣;皆知善之为善。斯不善矣;古有无相生,难易相成。”这是哪一派别的思想() ["儒家","道家","墨家","法家"]
()是DCS的产品结构中的第三代典型产品。
盐水渍菜