比例死亡比研究

  • 网络proportional mortality ratio study
比例死亡比研究比例死亡比研究
  1. 钢铁工人比例死亡比的研究

    Proportional mortality ratio study of iron and steel workers

  2. 对全国20个油毡厂工人的癌症和其它几种慢性病进行了比例死亡比的研究。

    A study on proportional mortality ratio of cancer and some other chronic diseases among workers in 20 asphalt felt-making factories is reported .